Provide API to return float values for amplitude instead of int

[FilippoVigani]

Is your feature request related to a problem? Please describe.
I'm having issues with low volume audio files, where most of the audio results with an amplitude of 0 or at most 1, so when I draw the wave I can only see dots or in case of a value of 1 a bar spanning the whole height (there are no in-betweens).

Describe the solution you'd like
I would like to be able to get float values instead of int in ranges 0-100 so I can be more precise when drawing the wave, and values aren't coerced to 0 or 1 in case of low volume. That way if values were like 0.001, 0.004, 0.006, the resulting would still result in non-zero height bars.

Describe alternatives you've considered
I can't think of any alternatives.

Additional context

[thedroiddiv]

@lincollincol Open to contributions? I can work on this.
Can be configured through a flag, or we can keep the native code return floating points, in java we can normalize it to 100 and return if amplitudeAsIntegerList or amplitudeAsList if floating.