optimize: Improve mod versions request to Modrinth

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.

launcher/modplatform/flame/FlameAPI.h

@@ -25,8 +25,8 @@ class FlameAPI : public NetworkModAPI {
             .arg(args.version);
     };
 
-    inline auto getVersionsURL(const QString& addonId) const -> QString override
+    inline auto getVersionsURL(VersionSearchArgs& args) const -> QString override
     {
-        return QString("https://addons-ecs.forgesvc.net/api/v2/addon/%1/files").arg(addonId);
+        return QString("https://addons-ecs.forgesvc.net/api/v2/addon/%1/files").arg(args.addonId);
     };
 };