Add adjustable makeup gain to DynamicsCompressorNode #2639

Describe the feature
The DynamicsCompressorNode specification currently has a fixed makeup gain derived from its other parameters: https://webaudio.github.io/web-audio-api/#computing-the-makeup-gain

While automatic makeup gain is convenient in some use cases, some users of the Web Audio API want more control over the makeup gain. For instance see discussions here:

• Limiter not working as expected, i.e. -100 still lets audio through Tonejs/Tone.js#1353
• https://crbug.com/372198644

We could add a way for developers to control the makeup gain behavior.

Is there a prototype?
No.

Describe the feature in more detail
I propose allowing users to control makeup gain directly in DynamicsCompressorNode by adding the following:

• An AudioParam, makeupGain, which represents the makeup gain value in dB
• An addition to DynamicsCompressorOptions, makeupGain, of type (float or MakeupGainOptions), where MakeupGainOptions can be an enum with the value "automatic"
  • If makupGain is "automatic", the default, then the current behavior in the spec is used
  • If makeupGain is a float, then that is the fixed makeup gain in dB (with 0 meaning no makeup gain)

I think the basic idea of the above would work well, but we can also change the details or discuss alternative approaches.