refactor: Snowflake batch export (#18427)

* feat: Add test utilities module

* feat: Add new fixtures to conftest.py

* refactor: Use new fixtures/utilities in S3BatchExport tests

* chore: Update tests README

* refactor: Make exclude_events and interval fixtures available for all

* refactor: Use new fixtures/utils in bigquery tests

* chore: Mark all tests as pytest.mark.django_db

* refactor: Use new fixtures/utilities in PostgresBatchExport tests

* fix: Test for exclude_events

* fix: Apply indirect fixture

* refactor: Use new fixtures/utilities in RedshiftBatchExport tests

* refactor: Backfill tests use new fixtures/utilities

* fix: Skip tests that require google credentials

* refactor: BatchExport tests use new fixtures/utilities

* chore: Update docstrings

* refactor: Snowflake batch export is now async

* fix: Snowflake's execute_async doesn't support PUT

* test: Add proper Snowflake tests

* test: Update mock tests

* test: Generate events early and late

* test: Do not pass events_to_exclude as they are excluded anyways

* typo: In tests readme

Co-authored-by: Brett Hoerner <[email protected]>

* typo: In test docstring

Co-authored-by: Brett Hoerner <[email protected]>

* typo: In test data

Co-authored-by: Brett Hoerner <[email protected]>

* test: Do not pass events_to_exclude as they are excluded anyways

* Update query snapshots

* Update query snapshots

* fix: Support multiple file uploads

* feat: Add heartbeat support in Snowflake

* chore: Update logging levels

* fix: More asyncio

* fix: Typing

* chore: Add heartbeat timeout

* chore: Update log line

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Co-authored-by: Brett Hoerner <[email protected]>
Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>