Add medal unlock components

[cl8n]

• depends on Add medals cache and clean up UserAchievement #9610

this is a proposal for an interface to award medals from osu-web

each medal is a queueable event listener that extends MedalUnlock. basic flow is

• $event type-hints the events it will listen for
• shouldHandle() tests whether the received event is actually relevant to the medal unlock -- checks in here should be inexpensive bc it runs synchronously after the event is dispatched. if true, the handler will be queued as a job
• getApplicableUsers() gets the users that may unlock the medal, based on the event and any info saved at queue time (getQueueableState())
• shouldUnlockForUser() tests whether a user will unlock the medal, if they didn't have it already

medal unlocks won't run without a corresponding entry in osu_achievements where enabled=1, so it's safe to either add the implementation before the db entry, or add a disabled db entry first and enable it after implementation.

the event-driven design is partly so medal logic is in one place, and partly so hush-hush medals can be easily dropped in from a closed-source repo and Just Work:tm:. kind of over-engineered lol but it should be easy to make lots of different kinds of medals with this. I have some random example medals & tests at https://github.com/cl8n/osu-web/tree/medal-examples and https://github.com/cl8n/osu-web-hush-hush-medals

[peppy]

For the hush-hush portion, is there already premise for this existing? Feel free to PM me example usages, because I can't immediately think of any which wouldn't be score related.

[cl8n]

not really, I have some ideas for hush-hush but it's not the immediate reason I was working on this. will PM though

[nanaya]

This looks like non trivial to deploy with docker?

Might as well create a separate service where osu-web just forwards all received requests to? It can then send back medal generation request to osu-web through interop interface.

[peppy]

I think the modularity (ie. file parsing) should be removed if we just want to get some new web-based medals implemented, since it's only there for hush-hush (which we don't even know if we need/want).