repository: monkey patch pyro connection handling to detect clients going away When a pyro client goes away we need to close their session (to release their cnxset). Add a dict to the repository mapping pyro client threads to session object. Closes #2932058

notification: use viewargs for notif_entity_updated instead of transaction_data Now that notifications use separate sessions, they can't rely on the original transaction_data being around, so pass the data through view arguments instead, so the notification view knows what changed on updated entities. Closes #2936180

notification: properly handle cnx and lifetime of the hijacked session When we create a session for the notification rendering, we need to 1) give it a cnxset 2) commit and close it after we're done 3) restore the original session for subsequent notifications This changes the ordering of actual mail sending, since there are several different commits involved, but I don't see a way to fix that short of restoring hijack_user. Related to #2934523