Stage tiers

[tsa96]

Initially we weren't going to support let submitters/approvers set tiers for stages, @jason-e was the main advocate of not supporting it. But we've been discussing RJ/SJ maps in today's meeting, and Mac brought up RJ courses often being tiered. Plus, some stages on surf/bhop do have tiers, e.g. omnific.

Approach we decided on was to make stage tiers optional, where the submitter can choose whether they want tiers or not. If yes, they must suggest tiers for every stage. Reviewers will only be able to suggest tiers for stages if the submitter selected to tier it. Submitter and mods should be able to switch to enable stage tiers.

In the leaderboard selection UI, we should try to subtly set the colour of the stage button based on the tier, and have a tooltip - showing it outright would really clog up the UI and it usually isn't super important.

Since this can easily be tacked on to my on-going work, I'm self-assigning and not going to bother writing a precise spec right now.

[tsa96]

From team meeting discussions we sound pretty ambivalent to this and it's a lot of work and awkward in terms of UI/UX. Going to move off the Map Submission board, lower priority, and if we get a lot of requests for this after 0.10.0 release we could reconsider.