API MHR - Remove all references to DB2

[arlentees]

MHR API remove all legacy DB2 code and references.

• update configuration
• update models
• update data validation
• update unit tests

Also MHR API setup for GCP CI/CD scripts:

• Update to use poetry
• Update logging
• Update source code format convention with black
• Update CI and local db setup to use alembic db upgrade

[LizGovier]

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