adding install & update counting to the store

[PartyWumpus]

This adds two integer fields to the Artifact table, downloads and updates to count the installs for each plugin. It also adds an /increment endpoint which anyone can visit at any time to add one to either the downloads or updates for a plugin. (downloads is only incremented on the first install of a plugin)

We don't really need the updates field, i just thought it would be fun to track it as well.

TODO:

• Test it locally lol
• Add migration to extend the database properly
• Add CI tests
• Add rate limit somewhere (cloudflare limit appears to be 10s)
• Wait for Add sorting by name or creation date to the /plugins endpoint #51 to finish and then add an option to sort by number of downloads (and maybe by updates but idk 🤷)

[PartyWumpus]

endpoint is now /increment/{version_hash}?isUpdate=bool and recorded per version.

[PartyWumpus]

uncertain how i would properly add a test for sorting by downloads or how to add rate limiting. other than those two questions the PR is done.

[PartyWumpus]

I've managed to add rate limiting per plugin per IP (2 a day). It uses redis so adds another docker container, but it could just store in memory instead if you'd prefer. I also have no idea if it will work properly behind the cloudflare proxy.