Enhancement: Allow player plugin menus to be added to the main menu via "Customize Menus"

[SamInPgh]

I would like to be able to add the Denon/Marantz AVR Settings plugin menu to the main menu via the "Customize Menus" function. Otherwise, it can only be accessed by selecting "Players" from the main menu, selecting the "three-dot" icon for a player, selecting "More" from the dropdown, and finally selecting the menu from the resulting page. The "Customize Menus" screen would need to have an additional category of "Player" menus displayed, e.g. "Player -> Denon/Marantz AVR Settings", "Player -> Don't Stop The Music" etc., depending on what plugins are installed. As an example, Material Skin facilitates this by allowing shortcuts to these menus to be placed on its home page.