Relocate common module for each platform

This is needed because velocity has adventure shaded. Velocity's common module does not need to shade adventure, while BungeeCord and Bukkit do have to shade the dependency in.

Common/build.gradle

@@ -23,7 +23,6 @@ blossom {
 }
 
 shadowJar {
-    exclude 'net/frankheijden/serverutilsupdater/**'
     exclude 'plugin.yml'
     exclude 'bungee.yml'
 }