* Add support for `strict_loading` mode on association declarations.
Raise an error if attempting to load a record from an association that has been marked as `strict_loading` unless it was explicitly eager loaded.
Usage:
```
>> class Developer < ApplicationRecord
>> has_many :projects, strict_loading: true
>> end
>>
>> dev = Developer.first
>> dev.projects.first
=> ActiveRecord::StrictLoadingViolationError: The projects association is marked as strict_loading and cannot be lazily loaded.
```
*Kevin Deisz*
* Add support for `strict_loading` mode to prevent lazy loading of records.
Raise an error if a parent record is marked as `strict_loading` and attempts to lazily load its associations. This is useful for finding places you may want to preload an association and avoid additional queries.