LB-1255: Allow to undo listen deletion

[Shelly011s]

Problem

LB-1255
Allow the user to undo a delete by providing an undo button in the notification.

Solution

I have added an api endpoint which unmarks the listen for deletion in the timescaledb. The undo button uses the endpoint to implement it.

Action

[amCap1712]

Hi! Thanks for the PR. We haven't finalized a couple of aspects of how we want to surface deleted listens/undo. Once we have done that, I can provide further feedback.