Provide feedback when Browser doesnt support webspeech or different sample rates

[angrave]

In Firefox dev console:

• "Uncaught (in promise) Error: Your browser does not support web speech recognition

and when the Show Frequency is selected-

• AudioContext.createMediaStreamSource: Connecting AudioNodes from AudioContexts with different sample-rate is currently not supported.

However there is no feedback to the user that webspeech cannot be used.

The Show Time Data visualization works FWIW.