[Traktor S4 Mk3] Screen support

[acolombier]

This is related to PR #12259.

New mapping feature:

• Record button can be use to toggle scrolling waveform
• Mute button can be use to minify widget and get full screen artwork
• New shortcut to set loop backward (the playposition is the endpoint instead of start point)
• Ability to change hotcue color with shortcut

Depends of:

• QML: Add scrolling waveforms #3967
• feat: controller screen renderer #11407
• Ability for controller to share data at runtime #12199
• Allow controller mapping to discard polling #12558
• Add PlayerProxy missing current track when created after loading #12559
• Add beatloop anchor to set and adjust loop from either start or end #12745

A branch with all dependencies can be used to test/use this feature while the above dependencies gets reviewed. Branch is acolombier:traktor-s4-mk3-updated

TODO:

• Documentation update

[ywwg]

can you pull in the latest main changes to resolve the conflict?

[ywwg]

I think my next request would be for overview explanatory comments on all the new objects / files -- mixxx project has a bad habit of not doing code documentation and I'd like to fix that.

[ywwg]

(ah, I'm getting confused between branches, no c++ in this PR)

[acolombier]

@ywwg Yes, this PR is only the mapping part (QML + JS), though I can take your comment for #11407

That being said, I agree with you - enforcing code documentation would be a great thing, even for QML. I'm just not so sure how it would look like tho. But I'm keep to do some work on this, so the first QML mapping kinda set standards for future contribution

[acolombier]

Cannot be completed due to rejection of #12199

Will be kept updated in acolombier:traktor-s4-mk3-updated for anyone interested

[ywwg]

Per discussion, this work is not abandoned but on the back burner while we do a proper design for controller data sharing.