Add Notification Sound Feature

[birdpump]

This PR adds notification sounds to the Meshtastic web interface. It resolves #183. I added a notification sound that is played when a new message is sent to a connected node via a DM or channel. I have also added a bell icon on the sidebar that enables/disables the notification sound, and notifications are enabled by default. I can think of a few issues, such as the notification sound playing but there being no indication of where the new message is, so it may be a bit confusing if a lot of channels are displayed. Marking this PR as draft to get some feedback on the implementation. Please let me know if the logic checks out and is proper. I am relatively new to React.

[Hunter275]

@birdpump This works great in my testing.

The only thing I could think to add is a few different notification sounds and a setting to change them. Could be per channel or system wide.

[smiba]

Not sure if it already exists (but I can't see it in your commits and haven't dug into the code), but it would be nice if this could work together with the browser's notification channel to allow more native OS notifications. (Web Push)

[birdpump]

Not sure if it already exists (but I can't see it in your commits and haven't dug into the code), but it would be nice if this could work together with the browser's notification channel to allow more native OS notifications. (Web Push)

I was planning on also adding web push when I get a chance, thanks for the suggestion.

[Hunter275]

One issue with this is we need to make a notification sound, some discussion was had around various possibilities but nothing was decided.

If you're able and willing to create a notification sound and let Meshtastic use it let us know.

In the mean time we should find a sound we can use without license issues.