Iterable adjustable stream slices

[avida]

Resolves #7558

Some users experience problems with Iterable export stream could not complete cause thay have large data and API close connection before request finished.

To solve this issue introduce adjustable slice algorithm.

This algorithm is following:

1. First slice have 30 days length.
2. When slice is processed by stream next slice range is calculated based on how much time took
   previous request processing and request rate limit.
3. Knowing previous slice range we can calculate days per minute processing
   speed. Dividing this speed by 4 (request per minute limit) we can calculate
   next slice range. Next range cannot be greater than 180 days

If processing of previous slice havent been completed, reset next range start date to previous slice
and reduce next slice range by 2 times.

In case if range havent been adjusted before getting next slice (it could
happend if there were no records for given date range), next slice would
have 180 days length.

[avida]

/test connector=connectors/source-iterable

🕑 connectors/source-iterable https://github.com/airbytehq/airbyte/actions/runs/1481612632
✅ connectors/source-iterable https://github.com/airbytehq/airbyte/actions/runs/1481612632
Python tests coverage:

	 ---------- coverage: platform linux, python 3.8.10-final-0 -----------
	 Name                                                 Stmts   Miss  Cover
	 ------------------------------------------------------------------------
	 source_acceptance_test/__init__.py                       2      0   100%
	 source_acceptance_test/base.py                          10      4    60%
	 source_acceptance_test/config.py                        75      8    89%
	 source_acceptance_test/conftest.py                     108    108     0%
	 source_acceptance_test/plugin.py                        47     47     0%
	 source_acceptance_test/tests/__init__.py                 4      0   100%
	 source_acceptance_test/tests/test_core.py              200     94    53%
	 source_acceptance_test/tests/test_full_refresh.py       38     27    29%
	 source_acceptance_test/tests/test_incremental.py        69     38    45%
	 source_acceptance_test/utils/__init__.py                 6      0   100%
	 source_acceptance_test/utils/asserts.py                 37      2    95%
	 source_acceptance_test/utils/common.py                  41     24    41%
	 source_acceptance_test/utils/compare.py                 62     25    60%
	 source_acceptance_test/utils/connector_runner.py        82     49    40%
	 source_acceptance_test/utils/json_schema_helper.py     115     14    88%
	 ------------------------------------------------------------------------
	 TOTAL                                                  896    440    51%
	 ---------- coverage: platform linux, python 3.8.10-final-0 -----------
	 Name                                  Stmts   Miss  Cover
	 ---------------------------------------------------------
	 source_iterable/__init__.py               2      0   100%
	 source_iterable/api.py                  159     69    57%
	 source_iterable/iterable_streams.py     107     15    86%
	 source_iterable/slice_generators.py      73      0   100%
	 source_iterable/source.py                15      6    60%
	 ---------------------------------------------------------
	 TOTAL                                   356     90    75%

[avida]

/publish connector=connectors/source-iterable

🕑 connectors/source-iterable https://github.com/airbytehq/airbyte/actions/runs/1490328082
✅ connectors/source-iterable https://github.com/airbytehq/airbyte/actions/runs/1490328082