[Dev]: Tournament imports and subscriptions

[TylerBloom]

Unmet Need:

There needs to be commands that allow for TOs to import a tournament that's been created using a different platform (such as the desktop app). For now, reasonable constraints can be put on this importing, such as you can only import tournaments that have yet to start. Once a tournament is imported, it will receive updates from the backend server, be updatable like a tournament created via a command, and be synced with the backend.