Newcomer month changes

[dunkOnIT]

BLOCKER 1+2: Merge wca-registration in monolith BLOCKER 3+4: Implementation of new competition page UI

1. Ability to mark a competition as a "Newcomer Month" competition
2. Ability to specify to reserve up to 50% of slots for that competition for newcomers (no id or ID of 2025)
3. A page (or a filter in the competitions page) that shows all upcoming competitions labeled as "Newcomer Month"
4. A visual tag somewhere on the competition page explicitly showing it as a Newcomer Month competition