qt/qml: Create the QmlBookmarkMenu and its custom button
This MR adds a player bookmark menu that the end user can trigger from the custom bookmark button (which will be part of our player presets). In this QMenu you'll find Titles, Chapters and Bookmarks with varying visibility depending on the Media. You can also open the 'Manage' bookmark dialog from within the menu.
I did additionnal work to provide a ListMenuHelper in order to avoid redundancy between the 'Playback' global menu and the player menu.
Also largely drew inspiration from the work of @chub in CheckableListMenu.
NOTE: !1637 (merged) should be merged first.
Edited by Benjamin Arnaud