cache results of SB requests

[kavorite]

See https://github.com/MegaAntiCheat/client-backend/issues/159. If we're to use https://steamhistory.net/api, we have to centralize the cache for it. As of now, this is the only place to do that.

Edit: Add acceptance criteria.

• [ ] Cached /sourcebans endpoint that returns SH API JSON payloads
• [ ] (enhancement) persist the cache in the database
• [ ] (enhancement) return response bodies augmented with times to live for cached results

[lili7h]

Updated my plan to remove the points that get solved by steamhistory and masterbase caching

[kavorite]

As per https://github.com/MegaAntiCheat/client-backend/issues/159#issuecomment-2174557884, no longer strictly necessary