Move pixldc commands into PIXL CLI

[milanmlft]

Fixes #392

• **Add pixl dc CLI command as a wrapper around docker compose
• Remove pixldc
• Update docs

Periphery changes:

• Use common pixl-db envvars for orthanc-anon
• Remove obsolete cli._utils

[codecov]

Codecov Report

Attention: Patch coverage is 96.87500% with 2 lines in your changes missing coverage. Please review.

Project coverage is 83.04%. Comparing base (1c356f2) to head (b6ebc33).

Files	Patch %	Lines
cli/src/pixl_cli/_docker_commands.py	93.93%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #411      +/-   ##
==========================================
- Coverage   83.26%   83.04%   -0.22%     
==========================================
  Files          78       76       -2     
  Lines        3268     3061     -207     
==========================================
- Hits         2721     2542     -179     
+ Misses        547      519      -28     

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[stefpiatek]

Looking nice, adding in a couple of suggestions, we can try them out on the GAE this afternoon as well

[milanmlft]

Reverted back to using docker compose directly in run-system-test.sh because attempting to use pixl up/down requires the following:

• They need to be run from the project root directory (though the exact reason for this is still vague to me)
• They require all of the environment variables in test/.env to be set, because running the CLI through Python results in a series of imports and config() calls, which will fail when the envvar is not set

There's a couple of workarounds for this, like temporarily copying over the test/.env file to project root, or loading the test/.env file through Python. But I'm going to leave it at this because this PR already took way too much time for what should have been a simple change 🫠

More importantly though, I think this points to some not-so-ideal design choices in the way we're handling these environment variables and .env files. Because when I'm running pixl down, I don't really care whether RABBITMQ_HOST is defined or not, but at the moment that will result in an error. Might be worth having a think about!

[stefpiatek]

⭐ All working nicely on the GAE, though couldn't do dry run with the version of docker so tested out the prod volumes locally.

I think probably best to make just a pixl dc subcommand which is a wrapper around a subprocess to docker compose, as the aim is to make this an easier experience and then we don't have to document what the args are for docker compose etc.

Happy for you to merge once you've done that