Create a centralized, non-volatile repository of all projects known to all sources

Since this could have a major performance impact, I'm bumping it.

If I'm reading the code correctly, every unique $SOURCE_PLUGIN_ID/$SOME_LOCAL_ID gets a separate key set? If this numbered into the thousands or tens of thousands I don't this kv is the best place, especially being the place I most associate with Redis, and these IDs are not values I assocaited with require super fast runtime read/write. Would it be better to use a cache bin?

@sime, the problem with a cache bin is that it can be wiped out at any time, and since this data has to persist across multiple requests, we need to guarantee that it can't just disappear because some other user did a cache clear while you were trying to install something. So I needed something "stickier", thus the key-value store.

And it would be so easy to swap KV with something else if needed later.

Everything else makes sense and it's worth a maintainer having a look - the key thing I see is changes to how the projects are uniquely identified and then all the services are adjusted to support that.

tim.plunkett → credited chrisfromredfin → .

Merged !511 🎉