DM-48635 Add tooling for local testing of consdb

[bbrondel]

This addition creates the ability to easily set up a local deployment of consdb. The steps are

1. Make sure you have Docker and Docker Compose
2. Gather some header service YAML files (optional)
3. Create a local .env file following the instructions in docker-compose.yml (optional)
4. Run docker compose up --build in the extras directory

[JeremyMcCormick]

Minor suggestion: I would put container-related config in a top-level directory called docker rather than extras and then organize its content accordingly. This is the convention I have seen most other projects use for these types of files.

[rcboufleur]

I noticed this file was added, but I’m not entirely sure how it fits into the current changes. Any particular reason?

[rcboufleur]

Looks good to me!