Replace HttpAvailabilityStrategy read helper methods with Stream.read_full_refresh

[girarda]

What

The HttpAvailabilityStrategy uses helper methods to read the first record of Stream in full refresh.
It should use the new Stream.read_full_refresh method instead

Acceptance criteria

• HttpAvailabilityStrategy.check_availability uses the stream’s read_full_refresh to check if a record can be read
• The methods in airbyte-cdk/python/airbyte_cdk/sources/streams/utils/stream_helper.py are deleted

[farheenfathimaa]

#31384