[libadwaita] (13 commits) Non-fast-forward update to branch wip/exalm/borderless

[Alexander Mikhaylenko <alexm src gnome org>]

The branch 'wip/exalm/borderless' 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:

  c8086e2... stylesheet: Update menu button style
  4b09981... Add AdwSplitButton
  8d372bb... Add AdwButtonContent
  e885d4a... stylesheet: Remove separator margin for non-menu popovers
  383e517... stylesheet: Use toolbar style for header bars and action ba
  425d751... stylesheet: Reset toolbar styles for popovers
  969b663... stylesheet: Make GtkWindowControls buttons filled
  1dcf55a... stylesheet: Make image buttons square
  e641f3a... stylesheet: Specificity bump for spinbutton buttons
  f396e79... example

Commits added to the branch:

  3f76263... squeezer: Fix the threshold policy doc links (*)
  752768e... stylesheet: Update menu button style
  52dd49e... Add AdwSplitButton
  e33f07e... Add AdwButtonContent
  f69518a... stylesheet: Remove separator margin for non-menu popovers
  570443e... stylesheet: Use toolbar style for header bars and action ba
  af9ca59... stylesheet: Reset toolbar styles for popovers
  19e3960... stylesheet: Make GtkWindowControls buttons filled
  6dd583a... stylesheet: Make image buttons square
  c99efd4... stylesheet: Specificity bump for spinbutton buttons
  6e9510a... view-switcher-button: Set spacing in css and match buttons
  33e88b5... stylesheet: Add separator.spacer
  139d0e2... example

(*) This commit already existed in another branch; no separate mail sent