This change removes the obsolete Mongo database configuration that was
stored in the repository, now that the new web API migrates to Postgres.

This change updates the Docker Compose configuration to properly deploy
the API server, by passing the necessary Auth0 information to it.

This change merges the four main OpenDC development repositories into a
single Git repository and performs final organization of the repository.

This change prepares the opendc repository for a monorepo setup by
moving all files to the core/ directory. After all repositories have
been merged into this repository, we will move the correct files back.

This change will make the database image automatically import the schema
and test data.