Initial repository and Wagtail setup

[zerolab]

Covers CMS-73 and CMS-74.
The commits should be atomic.

• Bumps Python to 3.12, adds Wagtail 6.2.2 and Django to 5.1
• Docker/docker-compose. Dockerfile provisions for cached steps
• ruff, pylint, mypy for linting / type checking
• pytest for testing
• barebones Wagtail skeleton with a number of relevant blocks from Alpha

[MebinAbraham]

We should add a small section in the README about, Migrations:

• what it is (link to django docs for further reading)
• how to generate them
• when to generate them
• how to apply then.

[MebinAbraham]

LGTM, few minor comments to resolve.

[sanjeevz3009]

Reviewed!