[gnome-control-center] (12 commits) Non-fast-forward update to branch gbsneto/panel-headerbar-cleanup

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

The branch 'gbsneto/panel-headerbar-cleanup' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  db6e2b9... panel: Add titlebar to panels
  c271eea... panels: Switch to CcPanel content
  7f386ea... panels: Use new CcPanel helpers for title widgets
  b4b4039... display: Rework titlebar handling entirely
  2e25a69... panel: Remove cc_panel_get_title_widget
  2ff8877... shell: Remove cc_shell_embed_widget_in_header
  f155943... shell: Remove cc_shell_set_custom_titlebar
  f4fd2a4... window: Remove panel headerbar widgetry
  8ff42ed... window: Install action to navigate main leaflet

Commits added to the branch:

  34c3437... panel: Add titlebar to panels
  c28150d... panels: Switch to CcPanel content
  151e215... panels: Use new CcPanel helpers for title widgets
  b1e8ebc... display: Rework titlebar handling entirely
  2a6ef43... panel: Remove cc_panel_get_title_widget
  eeb7d24... shell: Remove cc_shell_embed_widget_in_header
  d06d281... shell: Remove cc_shell_set_custom_titlebar
  08c7306... window: Remove panel headerbar widgetry
  fb8b4f3... window: Install action to navigate main leaflet
  00cace1... applications: Switch ti AdwWindowTitle
  01ac1c4... window: Remove unnecessary calls to gtk_widget_show
  2366a6c... window: Improve transition between panels