Fix some issues with the protocol chooser and clean up its usage in GtkAccount

Review Request #533 — Created Feb. 26, 2021 and submitted — Latest diff uploaded

Information

pidgin/pidgin
default
e19cd8097c0a

Reviewers

Fix some issues with the protocol chooser and clean up its usage in GtkAccount

Added PidginProtocolStore and PidginProtocolChooser to the Glade catalog.
Updated the template for PidginProtocolChooser to use a GtkTreeModelSort to sort the list of protocols.
Ported the existing purple_protocols_* API use to pidgin_protocol_manager_*

Verified the new account dialog shows up properly with the protocol chooser sorted.
Verified that editing an account had the proper protocol selected.
Verified that changing a protocol on an existing account worked.