Main Menu unifications between drivers

[sonninnos]

Description

The goal was first to simply fix differences between "Load Content" menu, but found similar issues with "Main Menu" and Playlists. All drivers now share the same common code with same exceptions for these lists for easier maintenance and simplicity instead of having multiple platform specific exceptions etc in each driver. Basically all menu drivers skip their *_list_push() lists, but all code remains for later inspection.

• Move History and Favorites always together for quick access, and hide them under Playlists if they already are in Main Menu
• Move Netplay and Import Content to Main Menu to give more room for playlists
• Import Content follows the same option (Main Menu vs Playlists) with all drivers
• Show File Browser options in Load Content always, except in Kiosk Mode which also won't show all drives
• XMB & Ozone icon related fixes