Fix mediated groupchat invites
-
Push Invitation and Decline event much earlier
-
Refactor Logic to decide if mediated or not
Ejabbered 17.03 does add a
jabber:x:conference
namespace into mediated invites which has broken our logic -
Dont add a groupchat contact on invitation, always add the inviter to the roster
Fixes #8603 (closed), #8468 (closed)