…(add `AvailabilityStrategy` concept) (#19977)

* Rough first implememtation of AvailabilityStrategy s

* Basic unit tests for AvailabilityStrategy and ScopedAvailabilityStrategy

* Make availability_strategy a property, separate out tests

* Remove from DeclarativeSource, remove Source parameter from methods, make default no AvailabilityStrategy

* Add skip stream if not available to read()

* Changes to CDK to get source-github working using AvailabilityStrategy, flakecheck

* reorganize cdk class, add HTTPAvailabilityStrategy test

* cleanup, docstrings

* pull out error handling into separate method

* Pass source and logger to check_connection method

* Add documentation links, handle 403 specifically

* Fix circular import

* Add AvailabilityStrategy to Stream and HTTPStream classes

* Remove AS from abstract_source, add to Stream, HTTPStream, AvailabilityStrategy unit tests passing for per-stream strategies

* Modify MockHttpStream to set no AvailabilityStrategy since source test mocking doesn't support this

* Move AvailabilityStrategy class to sources.streams

* Move HTTPAvailabilityStrategy to http module

* Use pascal case for HttpAvailabilityStrategy

* Remove docs message method :( and default to True availability on unhandled HTTPErrors

* add check_availability method to stream class

* Add optional source parameter

* Add test for connector-specific documentation, small tests refactor

* Add test that performs the read() function for stream with default availability strategy

* Add test for read function behavior when stream is unavailable

* Add 403 info in logger message

* Don't return error for other HTTPErrors

* Split up error handling into methods 'unavailable_error_codes' and 'get_reason_for_error'

* rework overrideable list of status codes to be a dict with reasons, to enforce that users provide reasons for all listed errors

* Fix incorrect typing

* Move HttpAvailability to its own module, fix flake errors

* Fix ScopedAvailabilityStrategy, docstrings and types for streams/availability_strategy.py

* Docstrings and types for core.py and http/availability_strategy.py

* Move _get_stream_slices to a StreamHelper class

* Docstrings + types for stream_helpers.py, cleanup test_availability.py

* Clean up test_source.py

* Move logic of getting the initial record from a stream to StreamHelper class

* Add changelog and bump minor version

* change 'is True' and 'is False' behavior

* use mocker.MagicMock

* Remove ScopedAvailabilityStrategy

* Don't except non-403 errors, check_stream uses availability_strategy if possible

* CDK: pass error to reasons_for_error_codes

* make get_stream_slice public

* Add tests for raising unhandled errors and retries are handled

* Add tests for CheckStream via AvailabilityStrategy

* Add documentation for stream availability of http streams

* Move availability unit tests to correct modules, report error message if possible

* Add test for reporting specific error if available

… bug fix 7c17351

* turn off HttpAvailabilityStrategy as default (for now)

* Update imports accordingly