feat: add support for scaling BPM by different ratios using ControlPushButton

[mxmilkiib]

This change introduces the ability to scale the BPM of a track by different
ratios using ControlPushButton objects. Each button is connected to a lambda
function that calls the slotScaleBpm method with the corresponding BPM scale
factor.

[coveralls]

Pull Request Test Coverage Report for Build 9142569028

Details

• 411 of 2270 (18.11%) changed or added relevant lines in 103 files are covered.
• 175 unchanged lines in 53 files lost coverage.
• Overall coverage decreased (-0.2%) to 30.951%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/controllers/bulk/bulkenumerator.cpp	0	1	0.0%
src/controllers/hid/hidioglobaloutputreportfifo.cpp	0	1	0.0%
src/effects/backends/builtin/compressoreffect.h	0	1	0.0%
src/library/playlisttablemodel.cpp	2	3	66.67%
src/library/rhythmbox/rhythmboxfeature.cpp	0	1	0.0%
src/library/trackset/playlistfeature.cpp	5	6	83.33%
src/library/traktor/traktorfeature.cpp	0	1	0.0%
src/mixer/basetrackplayer.h	0	1	0.0%
src/musicbrainz/web/coverartarchivelinkstask.cpp	0	1	0.0%
src/preferences/dialog/dlgpreferences.cpp	0	1	0.0%

Files with Coverage Reduction	New Missed Lines	%
src/widget/wslidercomposed.cpp	1	0.0%
src/widget/wvumeterglsl.cpp	1	0.0%
src/library/serato/seratofeature.cpp	1	11.91%
src/track/track.cpp	1	60.18%
src/engine/controls/cuecontrol.cpp	1	69.55%
src/waveform/waveformwidgetfactory.cpp	1	0.0%
src/preferences/dialog/dlgpreferences.cpp	1	0.0%
src/waveform/renderers/allshader/waveformrendererrgb.cpp	1	0.0%
src/widget/openglwindow.cpp	1	0.0%
src/widget/weffectchainpresetbutton.cpp	1	0.0%

Totals
Change from base Build 8666677785:	-0.2%
Covered Lines:	31701
Relevant Lines:	102423

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💛 - Coveralls

[mxmilkiib]

Um, not sure how to squish those commits.