Reorder menu structure to make it clearer
- Move file related actions to "File" menu
- Move Effects to a new top level menu as they are not limited to the timeline (they work everywhere eg. for bin clips)
- Rename "Clean Project" to "Remove Unused Clips" to make it more obviouse what the action does
- Rename "Clip" menu to "Bin Clip" to make it clear the menu is only related to those (and not timeline clips)
- Add several icons
- Reorder several actions within there parent menu to have related actions next to each other