Add playlist random selector

[sonninnos]

Description

Due to "popular" demand let's allow doing quick random shuffling in playlists and explore lists. The goal is to have all menu drivers behave the same, which is to have the function in button Y (left).

• "Load Content" playlist list skips the first internal items and picks only actual added playlists, and same in Ozone sidebar
• Explore list skips "Search Name", "Add Additional Filter" and "Save as View"
• Moved current thumbnail cycling from button Y to X (top/search), and made it work only while in fullscreen thumbnail or in Quick Menu before content launch, since search makes no sense in those cases
• Ozone: Made footer legend to match
• Ozone: Refactored and removed code duplication in footer and footer tap press
• Ozone: Corrected footer OK/Back order regarding the OK/Back button switch order option for keeping the buttons always in specific order instead of simply switching the images
• GLUI: view mode switch changed from Y to Select

Currently the randomizer logic is a crude range pick which does not track previous hits in any way (except the current selection), but it can be improved later on.

Also:

• Allowed holding the button down for accelerated navigation, and fixed L2 & R2 acceleration
• GLUI: Had to set images+music+videos playlists also as "playlists" so that the randomizer works there too, which in turn forcefully enabled thumbnails, which is good for images, therefore added ways to remove the secondary thumbnail from images which is a duplicate of primary, and both images from music+videos, since they can't show anything anyway
• Related naming conventions and nits

Suggestions and more testing are more than welcome as always.

Related Issues

Closes #7471
Closes #13109

[6lackmag3]

Thanks for adding that! Would be cool if we could use it for some kind of System Demo Mode, where you can choose particular playlist and random selector will change game every 3, 5 or 10 minutes. Could be used for challenge runs for sure. Or just have random games running in the background on second monitor or tv, like attract-mode or smth.