This uses more arguments in the GET request for mod versions on the
Modrinth API, filtering what versions can be returned, decreasing load
on Modrinth servers and improving a little the time it takes for the versions to be
available to the user.
This also removes the now unneeded check on correct modloaders in
ModrinthPackIndex, since it is now filtered by the Modrinth server.
Lastly, this adds a couple of helper functions in ModModel.
This is done so that 1. ModAPI behaves more like an actual API instead
of just a helper, and 2. Allows for more easily creating other mod
providers that may or may not use network tasks (foreshadowing lol)
Moves all things related to creating the URLs of the mod platforms
that go to network tasks to a single place, so that:
1. Maintaining and fixing eventual issues is more straightforward.
2. Makes it possible to factor out more common code between the
different modplatform pages
