Venue: add "Publication Chair" as reader of all the accepted papers during the post decision stage

[melisabok]

In order to solve the permission issue of publication chairs having access to the accepted papers, camera ready revisions and accepted authors, I proposed to include this new role when the post decision stage runs:

1. Add the "Publication Chair" group as reader of the accepted submission if they are not public.
2. Add the "Publication Chair" as writers of the Authors/Accepted group so they can message the authors.
3. Add the "Publication Chair" as readers of the request form and invitee of the "Submission Revision Stage" so they can configure the camera ready revision.
4. Create a "Publication Chair" webfield component that shows the accepted papers and if they submitted the camera ready revision or not.

This role can be optional in the request form, if it is selected then execute the steps described above.