fix(ui): update MergeFileSorter button size from 'md' to 'sm'

Author: balazs-szucs

frontend/editor/src/core/components/tools/merge/MergeFileSorter.tsx

@@ -70,7 +70,7 @@ const MergeFileSorter: React.FC<MergeFileSorterProps> = ({
 
           <ActionIcon
             variant="secondary"
-            size="md"
+            size="sm"
             onClick={handleDirectionToggle}
             disabled={disabled}
             title={