We tried to remove all html tooltips in previous commits. Translators will love us if we stick to non-html strings. `\n` is translated as line break in the Transifex translation engine automatically.

Tested this plain text line in QT designer and it looks fine:
`CDJ Mode: \n - Cue button while pause at cue point = preview \n - Cue button while pause not at cue point = set cue point \n - Cue button while playing = pause at cue point \n Simple: \n - Cue button while pause = set cue point \n - Cue button while playing = play from cue point \nDENON Mode: \n - Cue button at cue point = preview \n - Cue button not at cue point = pause at cue point \n - Play = set cue point`

Would be cool if the tooltip could preserve the order of appearance for the different options. I have not check that, might be ok as it is.