Add support for the Edge TTS voices

[stemplock]

Add support for the tts service. https://github.com/rany2/edge-tts Please, if possible.

[jkyndir]

I had the exact same request. Microsoft Edge appears to have some amazing Voices

[ken107]

I think this is probably possible

[ken107]

It may or may not be possible, proof of concept needed.

The linked repo is a standalone Python program that calls Azure Speech Services and masquerades as the Speech component/extension in Microsoft Edge browser, by sending these headers when setting up the WebSocket connection:

{
  "Origin": "chrome-extension://jdiccldimpdaibmpdkjnbmckianbfold",
  "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.77 Safari/537.36 Edg/91.0.864.41"
}

I'm guessing Azure will reject the request if the headers aren't set correctly. But I'm not sure it's possible to set these headers in our Manifest V3 extension. Specifically:

1. Does the declarativeNetRequest API allow modifying these two privileged headers (Origin and User-Agent), and
2. Does the modification apply to the WebSocket setup requests