fix: Use nickname provided in subscription requests everywhere

The nickname is now also shown in the notification and passed to the AddContact dialog, which afterwards adds the nickname to the roster.

gajim/gtk/notification_manager.py

@@ -66,15 +66,15 @@ def _on_destroy(self, *args: Any) -> None:
 
     def _add_actions(self) -> None:
         actions = [
-            ('subscription-accept', self._on_subscription_accept),
-            ('subscription-deny', self._on_subscription_deny),
-            ('subscription-block', self._on_subscription_block),
-            ('subscription-report', self._on_subscription_report),
+            ('subscription-accept', self._on_subscription_accept, 'as'),
+            ('subscription-deny', self._on_subscription_deny, 's'),
+            ('subscription-block', self._on_subscription_block, 's'),
+            ('subscription-report', self._on_subscription_report, 's'),
         ]
         for action in actions:
-            action_name, func = action
+            action_name, func, typ = action
             act = Gio.SimpleAction.new(
-                f'{action_name}-{self._account}', GLib.VariantType.new('s'))
+                f'{action_name}-{self._account}', GLib.VariantType.new(typ))
             act.connect('activate', func)
             app.window.add_action(act)
 
@@ -123,14 +123,14 @@ def _on_subscription_accept(self,
                                 _action: Gio.SimpleAction,
                                 param: GLib.Variant
                                 ) -> None:
-        jid = param.get_string()
+        jid, nickname = param.get_strv()
         row = self._get_notification_row(jid)
         self._client.get_module('Presence').subscribed(jid)
         jid = JID.from_string(jid)
         contact = self._client.get_module('Contacts').get_contact(jid)
         if not contact.is_in_roster:
             open_window('AddContact', account=self._account,
-                        jid=jid, nick=contact.name)
+                        jid=jid, nick=nickname or contact.name)
         if row is not None:
             row.destroy()
 
@@ -189,9 +189,12 @@ def add_subscription_request(self,
             new_row.connect('destroy', self._on_row_destroy)
             self.add(new_row)
 
-            contact = self._client.get_module('Contacts').get_contact(
-                event.jid)
-            text = _('%s asks you to share your status') % contact.name
+            nick = event.user_nick
+            if not nick:
+                contact = self._client.get_module('Contacts').get_contact(
+                    event.jid)
+                nick = contact.name
+            text = _('%s asks you to share your status') % nick
 
             app.ged.raise_event(
                 Notification(account=self._account,
@@ -330,7 +333,10 @@ def __init__(self,
         accept_button.set_valign(Gtk.Align.CENTER)
         accept_button.set_action_name(
             f'win.subscription-accept-{self._account}')
-        accept_button.set_action_target_value(GLib.Variant('s', self.jid))
+        accept_button.set_action_target_value(GLib.Variant.new_strv([
+            self.jid,
+            user_nick or ''
+        ]))
         self.grid.attach(accept_button, 3, 1, 1, 2)
 
         more_image = Gtk.Image.new_from_icon_name(