Allow non-quantized tempo-multiple frequencies on LFOs

[GeorgesOatesLarsen]

Howdy -- currently tempo options for LFO include:

• Seconds
• Tempo
• Tempo Dotted
• Tempo Triplets
• Keytrack

Seconds & Keytrack are based on true time, so altering the BPM of the song in a DAW does not impact it.
Tempo, Tempo Dotted, Tempo Triplets are based on BPM, so altering the BPM of the song does impact it. However, it is quantized -- Only clean fractions of the song tempo are possible values.

I would like to request a sixth option: BPM Multiple, a floating-point multiple of the BPM.

This would allow for any floating multiple of the BPM to be used as the LFO frequency. This would allow for, for instance, continuous transition between integer multiples (or fractions) of the BPM, which is currently not possible.

Ideally this mode would have a scale premultiplier which is identical to the existing tempo options, though this is not necessary for it to be functional.

Alternatively, add a continuous-value multiplier to the existing clean-fraction tempo options.

(I don't seem to have permissions to tag this as an enhancement or feature request? Sorry if I am just dumb)