[FEAT] Refactor competitions into a global store

[joms]

Proposed functionality
Competitions should live in a global store, like Context or similar. The reason for this is its extent all over the application. In todays solution it's fetched multiple times in multiple ways, and it should be baked into a single entity.

Use case
This will make handling competitions better, but also ensure that the user has a more concise experience with less spinners running.