Publish talk to ems

When a talk is accepted (or rejected) it is published to ems. Also need to update ems if an already published talk is changed

Start by locating where talk acceptance and rejection are handled, then find the existing integration or entry point for publishing talks to EMS. Trace what happens when an already published talk changes. Done means accepted or rejected talks are published to EMS and later changes are propagated.

Written by the indexing model from the issue text.