feat: add mod update dialog

This subclasses the Review mods dialog to make a "Update review" one.
Also, all the necessary components built until now are put together in a
coherent unity that checks and generates metadata on-the-fly and checks for
mod updates, while giving and receiving feedback to the user.

Signed-off-by: flow <flowlnlnln@gmail.com>

launcher/ui/dialogs/ScrollMessageBox.ui

@@ -6,7 +6,7 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>400</width>
+    <width>500</width>
     <height>455</height>
    </rect>
   </property>