LoopingControl: Replace most double sample positions with mixxx::audio::FramePos

[Holzhaus]

Based on #4186.

[coveralls]

Pull Request Test Coverage Report for Build 1132407919

• 247 of 300 (82.33%) changed or added relevant lines in 4 files are covered.
• 8 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.02%) to 25.96%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/engine/controls/cuecontrol.cpp	2	3	66.67%
src/engine/controls/loopingcontrol.cpp	236	288	81.94%

Files with Coverage Reduction	New Missed Lines	%
src/engine/enginevumeter.cpp	1	90.24%
src/engine/controls/loopingcontrol.cpp	7	82.64%

Totals
Change from base Build 1127725238:	-0.02%
Covered Lines:	19981
Relevant Lines:	76967

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💛 - Coveralls

[Holzhaus]

Marked as draft until prerequisite has been merged.

[uklotzde]

I only found a minor typo. Please check why codespell didn't detect this?

Thanks for not modifying the existing code. This helps to quickly review such refactorings. With the additional type-safety updating the code late becomes much safer.

[uklotzde]

I have verified that our codespell hook doesn't work.

[uklotzde]

Since no one else showed up for a review let's merge. LGTM