v3.0.0: Completeness stats, data deletion, Postgres, and refactoring

Summary

Support for completeness stats and deleting datasets, as well as a change from Alpine to Debian and from SQLite to Postgres

What's Changed

• PR dispatch for CanDIGv2 (DIG-1230) by @justin-ys in #266
• change base image from alpine to python-debian by @kcranston in #268
• DIG-1308 Switch HTSGet to Postgres by @OrdiNeu in #271
• DIG-1301: Delete genomic data by @OrdiNeu in #270
• DIG-1235, 1237: htsget returns completeness stats by @daisieh in #272
• Bump flask from 2.2.2 to 2.2.5 by @dependabot in #269
• Bump uwsgi from 2.0.21 to 2.0.22 by @dependabot in #267
• DIG-1329, DIG-1330: Dataset to cohort refactoring by @daisieh in #273
• DIG-1301: finish delete cascades by @daisieh in #274
• Shrink test files for indexing in tests by @daisieh in #275

New Contributors

• @justin-ys made their first contribution in #266
• @OrdiNeu made their first contribution in #271
• @dependabot made their first contribution in #269

Full Changelog: v2.2.0...v2.3.0