Tempo slider handle gone if rate is out of rate range (synced or manually set)

[ronso0]

To reproduce A
- load a track into any deck, leave other decks empty
- tempo-sync loaded deck
(or tempo-sync to any BPM out of rate range)

To reproduce B
- load a track into any deck
- set BPM with controller so it's out of rate range
  engine.setValue(group,"bpm",newBpm);

Result:
Tempo slider handle is either gone or party visible, then gone when mouse hovers over it.

* mouse scroll on slider brings it back to limt of rate range
* right-click on slider (reset rate) brings it back within rate range
Previously it was also possible by moving the controller's tempo fader to its end points.
Not working anymore.

alpha-pre 6298
Linux 64bit

[ronso0 (ronso0)]

Probably caused by this PR
https://github.com/mixxxdj/mixxx/pull/1237

YEs, people do like slider handles visible.
And the side effect on controllers is massive because most controller have a Sync button but no reset button..

[Daniel Schürmann (daschuer)]

Fixed after discussion in
https://github.com/mixxxdj/mixxx/pull/1237
In
https://github.com/mixxxdj/mixxx/pull/1296

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/8880