Preferences Effects: left/right key in effect lists trigger hide/unhide

[ronso0]

Followup for #13329
Fixes #10580

Or should this rather be Alt + Left/Right, like the track move hotkeys?

[ronso0]

TODO
mention the keys in the description above the list views. This will invalidate the existing translations though..
As a workaround I may grab the tr string from the ui file and append the new hint in the cpp.
When merging to main we may then either update the string in the ui file or move it to the cpp (would allow to painlessly append more info in the future / point releases).