SQLite -> Postgres Test Migration

[naasanov]

Fixed tests to use Postgres instead of sqlite

Changes:

• Instead of using in memory sqlite, create a separate db for testing in the existing postgres container
  • Modified test_session conftest fixture
  • Added a new script to make this test_db and put this into the postcreate script
  • Updated CI tests to use postgres
• Made DB validate PID as 9 digits now that this works with tests
• Fixed issues unearthed by tests using postgres
  • Timezone stuff in complaint entity and party router

Extras:

• Added a check in create_db.py to see if the db already exists, so that expected behavior doesn't look like an error
• Made get_parties_nearby and get_parties_csv validate date format at middleware level with regex
  • Added tests for this as well
• Edited backend-tests action to run on PR for any branch instead of just main

Closes #143

[naasanov]

Necessary for async session fixture shenanigans

[naasanov]

Truncate instead of drop all tables so that tests don't take a million years

[github-actions]

Test Results Summary

302 tests  +16   302 ✅ +16   12s ⏱️ +4s
  1 suites ± 0     0 💤 ± 0 
  1 files   ± 0     0 ❌ ± 0 

Results for commit 041b637. ± Comparison against base commit e23a979.

This pull request removes 1 and adds 17 tests. Note that renamed tests count towards both.

test.modules.party.party_router_test.TestPartyNearbyRouter ‑ test_get_parties_nearby_validation_errors

test.modules.party.party_router_test.TestPartyCSVRouter ‑ test_get_parties_csv_validation_errors[params0]
test.modules.party.party_router_test.TestPartyCSVRouter ‑ test_get_parties_csv_validation_errors[params1]
test.modules.party.party_router_test.TestPartyCSVRouter ‑ test_get_parties_csv_validation_errors[params2]
test.modules.party.party_router_test.TestPartyCSVRouter ‑ test_get_parties_csv_validation_errors[params3]
test.modules.party.party_router_test.TestPartyCSVRouter ‑ test_get_parties_csv_validation_errors[params4]
test.modules.party.party_router_test.TestPartyCSVRouter ‑ test_get_parties_csv_validation_errors[params5]
test.modules.party.party_router_test.TestPartyCSVRouter ‑ test_get_parties_csv_validation_errors[params6]
test.modules.party.party_router_test.TestPartyCSVRouter ‑ test_get_parties_csv_validation_errors[params7]
test.modules.party.party_router_test.TestPartyNearbyRouter ‑ test_get_parties_nearby_validation_errors[params0]
test.modules.party.party_router_test.TestPartyNearbyRouter ‑ test_get_parties_nearby_validation_errors[params1]
…

♻️ This comment has been updated with latest results.