Reviewed the download count PR work and made some changes:
- Updated the download link route to include the mod's slug for easier identification.
- Moved rate limiter from the route middleware (the entire controller) to just the show method in the controller.
- Created a ModVersionPolicy that the controller can check against.
- Moves download increment logic into the model.
- Defers the call to the download increment logic (now run in the background)
- Updated the route to have a name, and the downloadUrl methods to build the URL dynamically using the route name.
- Wrote some tests to check URL building, download counting, and rate limiting.
# Conflicts:
# app/Http/Controllers/ModVersionController.php
# app/Providers/AppServiceProvider.php
