Websocket persistent notification: allow active controls right from the notification

**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_