Show where each item starts in the inspiration and sync lists

Items in the inspiration list and the sync result columns now each have
their own background box, alternating between two shades, with a small
gap between them. When a long name wraps over several lines it is
still clear which lines belong together. The sync columns keep their
alternating white and orange text.

tests/integration/test_sync_window.gd

@@ -113,7 +113,7 @@ func test_changed_titles_list_old_and_new_title() -> void:
 
     var vbox: Control = _node("SoundtracksChangedTitleVBox")
     assert_bool(vbox.visible).is_true()
-    assert_str((vbox.get_child(1) as Label).text).is_equal(
+    assert_str((vbox.get_child(1) as ListRow).text).is_equal(
             "FF7\nchanged title to\nFinal Fantasy VII")