action-bar: Add an action bar to the conversations list (2-panel)
This moves the actions from the headerbar to the action bar at the bottom of the conversations list when multiple conversations are selected. This changes is needed so that the user can still interact with the conversations when folded. This also hides the actions from the Headerbar and action bar when no conversation is selected.
adaptive in 50 minutes and 4 seconds (queued for 1 second)3 jobs for