[Feature Request] Record to wav format

[wxfred]

There I found a package support recording with wav encoding
https://stackoverflow.com/questions/65191193/media-recorder-save-in-wav-format-across-browsers
https://github.com/chrisguttandin/extendable-media-recorder

I simply changed the code in record.ts from

import BasePlugin, { type BasePluginEvents } from '../base-plugin.js'
import Timer from '../timer.js'
import type { WaveSurferOptions } from 'wavesurfer.js'
...

to

import BasePlugin, { type BasePluginEvents } from '../base-plugin.js'
import Timer from '../timer.js'
import type { WaveSurferOptions } from 'wavesurfer.js'
import { MediaRecorder, register  } from 'extendable-media-recorder'
import { connect } from 'extendable-media-recorder-wav-encoder'

await register(await connect())
...

and add any to the types of mediaRecorder (I don't know the right type, not familiar with ts, sorry)

class RecordPlugin extends BasePlugin<RecordPluginEvents, RecordPluginOptions> {
  private stream: MediaStream | null = null
  private mediaRecorder: MediaRecorder | any | null = null

It worked with

record = wavesurfer.registerPlugin(
  RecordPlugin.create({
    mimeType: 'audio/wav',
  }),
)

Please consider to support it, thx.

[katspaugh]

I suppose we could make the MediaRecorder object pluggable, perhaps via the options. Then you'd do something like:

import { MediaRecorder, register  } from 'extendable-media-recorder'
import { connect } from 'extendable-media-recorder-wav-encoder'

await register(await connect())

record = wavesurfer.registerPlugin(
  RecordPlugin.create({
    mimeType: 'audio/wav',
    MediaRecorder,
  }),
)

Pull requests are welcome!