Optimize user experience for Camera and Mic usage (permission)

[hpvd]

Initial checklist

• I understand this is a feature request and questions should be posted in the Community Forum
• I searched issues and couldn’t find anything (or linked relevant results below)

Problem

At this time, user experience of using Camera or Mic input is ok/standard.

Sometimes it's not that easy/straight forward to give uppy the needed permissions
To optimize this process, one could provide some help to users to make it work by handling some common browser errors.

Solution

maybe one can learn/adapt some ideas from
https://medium.com/joinglimpse/how-to-build-beautiful-camera-microphone-permission-checking-for-websites-e6a08415fa76

or even include it in uppy
https://github.com/helenamerk/mic-check

Alternatives

simply keep user experience of using Camera or Mic input at ok/standard quality :-)