Potential roadblocks for WebGL target.

[namark]

There have been a few inquires about Web support, and it's possible, but not going to be easy form what I can gather, so I'm documenting all the potential roadblocks I happen to come across.

• Qt does support Web Assembly to a degree, but it's not entirely clear if it's enough for our use case. The native client library aims to minimize dependencies on various modules and features either way, so this might not be problem.
• TBB Web Assembly support is WIP, again unclear if it's sufficient for us.
• Unity does not support Microphone API on the Web, so we will need an additional plugin for that. QtMultimedia is currently explicitly not supported (see the link in the first bullet-point), so we can't reuse the native code. Other possibilities are SDL2 microphone API, or re-using the audio input implementation from the Web SDK.

[digisomni]

We should add a note about this in the developer docs for the Unity SDK. https://docs.vircadia.dev/sdks/unity