* Various fixes for Batch Source
1. Create intermediate topic/subscription prior to function running in case auto topic creation is turned off
2. Fix possible NPE in CronTrigger when calling stop()
3. Stop all producers created in ContextImpl
4. Delete intermediate topic for batch source
Co-authored-by: NJerry Peng <jerryp@splunk.com>

Motivation
close() method never gets called in BatchSource

Co-authored-by: NJerry Peng <jerryp@splunk.com>

### Motivation

The async function test is relying on a race condition on when the counter is updated. 

With `pendingQueueSize=2`, the 3rd event is blocked on the queue until the 1st event is processed. That makes 1st and 2nd event to be triggered around the same time and the validation to fail, when we the 2nd event to be already done.

Additionally, there are multiple threads leaked by this test.

* Make Nar Extraction Directory configurable

* Fixed unittests
Co-authored-by: NSanjeev Kulkarni <sanjeevk@splunk.com>

Fixes #6519

### Motivation

Currently, Pulsar Functions not support Async mode, e.g. user passed in a Function in format :
```
Function<I, CompletableFuture<O>>
```
This kind of function is useful if the function might use RPCs to call external systems.

e.g.
```java
public class AsyncFunction implements Function<String, CompletableFuture<O>> {
    CompletableFuture<O> apply (String input) {
        CompletableFuture future = new CompletableFuture();
        ...function compute...
        future.whenComplete(() -> {
            ...  call external system  ...
        });
        return future;
    }
```

### Modifications
- add support for Async Functions support.

### Verifying this change
current ut passed.



* support func: Function<I, CompletableFuture<O>>

* add 2 examples

* add limit to the max outstanding items

Co-authored-by: NSanjeev Kulkarni <sanjeevk@splunk.com>

* Add subscribe position param for consumer of sink
Signed-off-by: Nxiaolong.ran <ranxiaolong716@gmail.com>

### Motivation

Adding support for state deletion for Functions.  Ran into a use-case where it would be nice to be able to let go of state wherein the key is changing but the data itself is ephemeral. 

### Modifications

I've reflected the changes in the bookkeepr API back through in the context and state context API's so that you can delete on a put by passing null or call the new api for delete.

### Verifying this change

This change added tests and can be verified as follows:
 - Running the unit tests available in the ContextImplTest and ContextStateImplTest

* Simplified assert statements in the tests. Switch to usage of static imports in tests. (Part 1)

* Simplify assert statements in the tests and use the appropriate assert statements. Switch to usage of static imports in tests. Remove unused imports (Part 2)

* Convert anonymous functions to lambda

* Replacing lambda with anonymous implementation, because lambda cannot be mocked

* Use classloading to load use code for functions

Upgrading to Mockito 2.28 and PowerMock 2.0. This a pre-step to be able to run CI with Java 11 / 12

* Added an explicit field in the function details for componenttype

* Fixed unittests

* Updated the defn of python pb file

* Added licence

* Took feedback into account

* Added unittest

Master Issue: #4042

Fixes #4042

Motivation

improve java functions API, when you need to publish the fields in the TypedMessageBuilder, there is no need to add a new publish method, just modify the interface in the TypedMessageBuilder.

* Allow to configure TypedMessageBuilder through a Map conf object

* Use constants for message confs

* Reverted previous change

* Use Long instead of Number

* Set key for message when using function publish

* fix unit test

* fix python test

* improving impl

* improving implementation

* add tests and examples

* fix bug

* fix bug

* fixing comments

* fix example

* addressing comments

* fix function

* Add Async State manipulation methods

* Fix build

* Fixed unittest

* Consolidating utils classes

* further refactoring

* adding missing class

* add license header

1) Collect input topics from the function details spec
2) Catch all errors during source/sink close since its user code

* fix: NPE when stats manager not initialized

* remove unnecessary imports

* add test

### Motivation
   when I study and read this module code , I fix some error like:
1. words error, such as JaveInstance -> JavaInstance, Recieved -> Received,  Unknwon -> Unknown, alterted -> alterted, Updare -> Update, etc.
2. remove not use import java class.
3. duplicated code in this  java class I extract method. 
4. javadoc  styles are consistent (not required)

### Modifications

minor fix up in pulsar-functions module

* On publish failures, log error and count them as sys exceptions

* Took feedback

Closes #3663 

* report sys errors when failed to produce sucessfully

* enhancing error message

* adding metrics to context publish

* enhancing error logging and adding java error handling

* fixing tests

* cleaning up

* addressing comments and fix bug

* cleaning up

* fix bug

* fix test

* check is none

* fix unit test

* cleaning up

* moved all windowing related code into its own submodule.

* added pom

* Added WindowFunction interface and implementation

* Fixed logic

* Update comments

* Took feedback into account

Clean up and correct properties to producer and consumers created by Functions/Sinks/Sources (#3315)

* clean up and correct properties to producer and consumers created by functions

* fix test

* cleaning up comment

* refactoring

* add sink and source prometheus stats

* fixing stuff

* fix bug involving consumer producer deadlock in functions

* fix unit test

* remove pulsar-client-schema

* shade avro dependencies in pulsar-client-kafka-shaded

* refactor api to separate module

* adding schema back

* cleaning up

* fix license issue

* fixing licenses

* cleaning up

* adding back lombok

* cleaning up

* fix bugs in python metrics

* instance expose metrics

* remove commented out code

* fix unit tests

* remove commented out code

* fixing test

* fix python instance test

* removing old code

* fix bug

* refactoring java metrics

* refactoring python metrics

* cleaning up code

* removing unneccessary code

* improving metrics format

* fixing test

* fix bugs and revising format

* fix bug

* fix for python3

* change user defined metric to summary

* renaming labels

* change back python

* Consolidate all inferMissing logic inside ConfigUtils.

* Removed tests that are already covered in windowconfigutils

* Reverted unneeded change

* Hooked up secrets function api with secret function implementations

* Fixed unittest

* Added more docs

* Took feedback into account

* Added Get and List source/sink functionality

* Fixed compile

* Removed test that doesnt make sense any more

* Fixed build

* Fixed logic

* Return error response

* Return response on error

* Fix unittest

* Fixed unittest

* Fixed unittest

* Fixed unittest

* Added get/list sinks tests

* Added get/list tests

* Add more unittests

* Added more unittests

* Added TODO

* Took feedback

* Fix unittest

* Fix unittest

* Fix unittest

* Fixed integration tests

* Fixed integration test

* Added restart/stop functionality to the sources/sinks

* Added getstatus method to sources/sink

* Fix integration tests

* Do Explicit Validation of Configs instead of annotations

* Remove all annotations from config files

* Removed validator related classes

* Removed unused imports

* Fix check logic

* fix compilation

* Fix unittest

* Fixed unittest

* Fixed unittest

* Validator tests should be done elsewhere

* Added unittest

* Fixed unittest

* Do not create any producer if the output type of a function is void

* Do not write if the record is null

* Revert the check for null