• Adds full mod uninstallation functionality, including removal from the database
• Adjusts the install button on mods to update or reinstall depending on the version state of the mod
• Adds proper mod updating functionality on the backend rather than relying on regular installs
  • This ensures that leftover artifacts from an old version are properly removed when updating to a new version that has fewer artifacts
• Improves the update-all functionality to only show the summary messages
• Some refactoring of various backend pieces

Closes #35