- More code cleanup and codestyle updates

- Fixed some possible nullref exceptions
- Methods signatures now have up to 3 parameters before breakaing down each parameter in a separate line
- Method invocations have the same rule, except the first parameter will be in the same line as the invocation to prevent some ugliness when passing lambas as arguments
- Applied many more codestyles
- Extensions folder fully reformatted

src/NadekoBot/Modules/Administration/Services/SelfAssignedRolesService.cs

@@ -27,9 +27,7 @@ public class SelfAssignedRolesService : INService
     }
 
     public SelfAssignedRolesService(DbService db)
-    {
-        _db = db;
-    }
+        => _db = db;
 
     public bool AddNew(ulong guildId, IRole role, int group)
     {