LateNight causes a bunch of warnings during startup

[Jan Holthuis]

On 2.3 branch, I get these when starting Mixxx with the LateNight/PaleMoon skin:

    Warning [Main]: QList::insert(): Index out of range.
    Warning [Main]: Cannot open file 'skin:/palemoon/buttons/btn___active.svg', because: No such file or directory
    Warning [Main]: WaveformSignalColors::fallBackDefaultColor - skin do not provide valid signal colors ! Default colors is use ...
    Warning [Main]: QList::insert(): Index out of range.
    Warning [Main]: /home/jan/Projects/mixxx/src/skin/legacyskinparser.cpp:1942 SKIN ERROR at skin:/controls/button_2state.xml:16 <PushButton>: Invalid <TooltipId> in skin.xml: "FIXME_waveforms"
    Warning [Main]: /home/jan/Projects/mixxx/src/skin/legacyskinparser.cpp:1942 SKIN ERROR at skin:/controls/button_2state_persist.xml:16 <PushButton>: Invalid <TooltipId> in skin.xml: "show_4decks"
    Warning [Main]: /home/jan/Projects/mixxx/src/skin/legacyskinparser.cpp:1942 SKIN ERROR at skin:/controls/button_2state.xml:16 <PushButton>: Invalid <TooltipId> in skin.xml: "FIXME_waveforms"
    Warning [Main]: /home/jan/Projects/mixxx/src/skin/legacyskinparser.cpp:1942 SKIN ERROR at skin:/controls/button_2state_persist.xml:16 <PushButton>: Invalid <TooltipId> in skin.xml: "show_4decks"
    Warning [Main]: /home/jan/Projects/mixxx/src/skin/legacyskinparser.cpp:1942 SKIN ERROR at skin:/controls/button_2state_persist.xml:16 <PushButton>: Invalid <TooltipId> in skin.xml: "FIXME_beatgrid_controls"

[ronso0 (ronso0)]

Yes, those are the issues we scheduled "to be fixed in another PR".
I already started the branch.
* missing TooltipIds for new controls (some we may also add to other skins)
* missing blank button border images which are supposed to supress warnings for buttons that use a standard template but have no icon assigned via xml
* overview color settings, will look into it

[ronso0 (ronso0)]

https://github.com/mixxxdj/mixxx/pull/2913

[Foss-4 (foss-4)]

PR merged, setting to fix committed. please adjust if I was too optimistic.

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/10029