Camera Connect and Disconnect events in the time line and triggers

**Describe what you are trying to accomplish and why in non technical terms**
Connect and Disconnect events should show up in the timeline and should be available in home assistant

**Describe the solution you'd like**
Building on https://github.com/blakeblackshear/frigate/issues/3846 I think it should be standard to show these in the events timeline send notices (maybe optional) as disconnected cameras both can be a major event and can sometimes be just a nuisance for WiFi cameras that do it often.

Maybe some additional filter settings like offline for x that would ignore the offline and online event if it was short.. The timer would start when the camera goes off, then if it is back on before the end no offline or online event is made.

IE I want to ignore short 5 min blips on a WiFi camera but want to know if a camera has completely been offline for 10 min when it went offline and when it came back.

**Describe alternatives you've considered**
A clear and concise description of any alternative solutions or features you've considered.

**Additional context**
Building on ignoring distortion it is important to know WHEN the cameras stopped recording so you know what time periods where missed. Especially if you are doing motion or object only recording as it will not be obvious.

Use issue #3846 as the starting reference, then inspect the existing timeline and Home Assistant trigger paths. Done should cover camera connect and disconnect visibility, optional notifications, and the proposed handling of brief outages.

Written by the indexing model from the issue text.