Live stream termination

[elv-serban]

Update live stream termination logic as follows:

• retrieve main meta
• if status is active and we have an edge_write_token
  • attempt to retrieve edge_write_token
    • if the edge_write_token is good and we can retrieve meta
      • check if the stream is 'stopped' - fail if it is not (we don't need to stop the stream here - the user is supposed to have stopped it already)

To terminate the stream:

• delete edge_write_token
• open a new write token from the main version
• set live_recording.status:
  • state: inactive
  • remove the edge_write_token (from both places)
  • stop_time: set to current time ISO format (this way we know the stream was previously active)
• finalize

[elv-gerald]

This is good. Logic makes sense to me.