Update pyproject as template for others

[spwoodcock]

(new PR, as I set my repo origin to the hotosm repo)

Final prep of config to use in osm-rawdata and fmtm-splitter.

Also:

• Added a pytest workflow using prebuilt CI image (faster, more stable).
• pandas and psycopg2 to the dependencies as they were missing.
• Docker packaging of code for fast usage / testing without having to manage system dependencies (particularly with CLI commands).
• Add doxygen to doc build action.

Solves #167 #109

[spwoodcock]

Ready to merge