[ENHANCEMENT] Pause and resume telrun operation

[axialregistrylogs]

Is your feature request related to a problem? Please describe.
There are times when we want to switch between automatic observations using telrun and manual observations; e.g. taking advantage of a gap in scheduled observing blocks, or being able to make real-time adjustments when troubleshooting an issue. Currently, the best way to do this is to stop telrun and then restart it later, but this results in telrun re-checking any observing blocks that have already been executed and causing later observations to be delayed and possibly canceled.

Describe the solution you'd like
Add the ability to pause telrun after it has started running and then resume it from the same point later.