Websocket persistent notification: allow active controls right from the notification

[mattdm]

Is your feature request related to a problem? Please describe.

The new websocket persistent notification actually provides a nice, quick shortcut to Home Assistant. However, after seeing it for a few hours, being told "Listening to Home Assistant via Websocket" is no longer really useful information.

I know the persistent notification must stay in order to keep Android from killing the app under pressure. That's fine. But as it is, the notification is using some of the most valuable and scarce UI real estate (and visible/attention space) to just show a basically useless static message and a rarely-useful configuration link.

This is part of several suggestions to improve this (linked by #2266).

Describe the solution you'd like

It would be awesome to be able to actually control frequently-accessed entities right from the notification. This could either be as actions (like #2269) or as buttons. Rather than taking you anywhere, though, clicking the button or text should toggle the linked entity, like clicking on a switch.

Describe alternatives you've considered, if any

This could be configured either per-server or per-user in the app. I have no strong feelings about which is right.

As with the dashboard link suggestions, more custom notification layout could be used. (Although AIUI Android is actively discouraging that now.)

Additional context

As noted, following on from https://github.com/home-assistant/android/issues/2266#issuecomment-1037329212_

[dshokouhi]

This request is similar to #1163 as that request also wants the action to fire a service call directly. So the proper fix here would also work for notifications in general. We should probably also match the behavior of notifications and fire back an event when selected. To keep things simple in both cases I think a toggle service would be easiest as opposed to having a user fill out a service call on mobile. More than likely a toast message should be shown upon success/failure as thats the only real visual indication we can give here.