Adds missing touch option to has_one association

Need to new line to break line in the markdown.

Update changelog for a bug-fix to read better [ci skip]

Don't fail ImageAnalyzer on unsupported types

Fix: #36065

The IamgeAnalyzer passes a image to ImageMagick without checking if the
image is supported by ImageMagick. This patch checks that image is
supported and if not logs an error and returns an empty hash instead of
raising an error. This is the same error handling we do when we
encounter a LoadError when mini_magick is not installed.

If we want to get alias resolved attribute finally, we can use
`attribute_alias` directly.

For that purpose, avoiding redundant `attribute_alias?` makes alias
attribute access 40% faster.

https://gist.github.com/kamipo/e427f080a27b46f50bc508fae3612a0e

Before (2c0729d8):

```
Warming up --------------------------------------
          user['id']   102.668k i/100ms
      user['new_id']    80.660k i/100ms
        user['name']    99.368k i/100ms
    user['new_name']    81.626k i/100ms
Calculating -------------------------------------
          user['id']      1.431M (± 4.0%) i/s -      7.187M in   5.031985s
      user['new_id']      1.042M (± 4.2%) i/s -      5.243M in   5.039858s
        user['name']      1.406M (± 5.6%) i/s -      7.055M in   5.036743s
    user['new_name']      1.074M (± 3.6%) i/s -      5.387M in   5.024152s
```

After (this change):

```
Warming up --------------------------------------
          user['id']   109.775k i/100ms
      user['new_id']   103.303k i/100ms
        user['name']   105.988k i/100ms
    user['new_name']    99.618k i/100ms
Calculating -------------------------------------
          user['id']      1.520M (± 6.7%) i/s -      7.574M in   5.011496s
      user['new_id']      1.485M (± 6.2%) i/s -      7.438M in   5.036252s
        user['name']      1.538M (± 5.4%) i/s -      7.737M in   5.049765s
    user['new_name']      1.516M (± 4.6%) i/s -      7.571M in   5.007293s
```

Fix sliced IN clauses to be grouped

Follow up of #35838.

And also this refactors `in_clause_length` handling is entirely
integrated in Arel visitor.

* Avoid duplicated `@new_record` assignment
* Extract `define_attribute_methods` into `init_internals`

Follow up to b1458218.

Remove redundant test setups in log_subscriber_test

Remove action_controller.perform_caching from api app's configs

Minor API doc fix

[ci skip]

Resurrect external JS/CS generation

As suggested in https://github.com/rails/rails/issues/35602#issuecomment-485833483, because we don't provide view caching and doesn't include `ActionController::Caching` for api apps, we should also avoid generating

```ruby
config.action_controller.perform_caching = true
```

for those api apps. So it won't confuse people.

**But because `perform_caching` will be `true` if not set, the behavior of the app would still be the same without these configs.**

Because controllers' `perform_caching` config is `true` by default, it
means we actually enable the caching in all those tests implicitly (and
it works). Which also means we can avoid repeatedly declaring that and
just specify it once in the setup method (just for declaration).

Update document about perform_caching's default value [ci skip]

Clarify that both `config.action_controller.perform_caching` and
`config.action_mailer.perform_caching`'s default are `true`. This
default is set in `AbstractController::Caching`.

One can verify this by commenting out all

```
@controller.perform_caching = true
```

in `actionpack/test/controller/caching_test.rb` and run the tests. They
should still pass.

Make docs on form_with_generates_ids config option match the value

[skip ci]

Update comment in attribute_method_matchers_matching

Remove reminiscences from previous documentation

Add attribute_names to ActiveModel::Attributes

Add ActionController::Caching into api app's document [ci skip]

Use ActiveJob 5.2 retry logic for old jobs

In #35861 documentation for `after_save_commit` was added, but also old
documentation was adapted. I think adapting the old documentation is not
necessary because there are already examples for `after_commit` on
`:destroy` above. On top of that the action invoked by the callback on
`:destroy` (`:log_user_saved_to_db`) talks about saving when the object
is destroyed, which can be misleading.

As I believe the documentation added by #35861 is already enough this
patch removes the modified part, which made sense before adding docs for
`after_save_commit` but is already covered by other parts of this guide.

Deprecate `where.not` working as NOR and will be changed to NAND in Rails 6.1

The current comment here is from 2011 and its original context has
changed completely. The plain matcher will not "match every time"
anymore since the code now filters all matchers, and only selects those
for which the captured attribute is valid.

To avoid confusion, I updated the comment. For more discussion, see:

https://github.com/rails/rails/pull/36005

Rails doesn't support view caching in api controllers by default but the
document didn't clearerly declare this nor the manual config needed
after including the module manually. So we'll see people get confused
like #35602.

[Matilda Smeds & Xavier Noria]

This adds `.attribute_names` and `#attribute_names` to
`ActiveModel::Attributes` along the same lines as the corresponding
methods in `ActiveRecord::AttributeMethods` (see
[`.attribute_names`][class_method] and
[`#attribute_names`][instance_method].

While I was here I also added documentation for '#attributes', which I
added in 043ce35b. The whole class is still `#:nodoc:` so I don't
think this will have any effect for now.

[class_method]: https://github.com/rails/rails/blob/cc834db1d0815744cfa173813c05d928e008e167/activerecord/lib/active_record/attribute_methods.rb#L154-L160
[instance_method]: https://github.com/rails/rails/blob/cc834db1d0815744cfa173813c05d928e008e167/activerecord/lib/active_record/attribute_methods.rb#L299-L301

This commit more or less undoes 9b5401fc, restores autoloaded? not to
touch the descendants tracker, and autoloaded_constants because it is
documented in the guide.