[libadwaita] (29 commits) Non-fast-forward update to branch wip/exalm/dark

[Alexander Mikhaylenko <alexm src gnome org>]

The branch 'wip/exalm/dark' 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:

  b7bfc4a... Add AdwSettings
  1d865ca... Add AdwStyleManager
  2d29f74... application: Proxy AdwStyleManager API
  9d6dbcf... demo: Rework the dark mode button

Commits added to the branch:

  907ae0f... stylesheet: Update menu button style (*)
  6eee9ae... Add AdwSplitButton (*)
  af2be5a... Add AdwButtonContent (*)
  0cd2703... stylesheet: Remove separator margin for non-menu popovers (*)
  f1b5704... stylesheet: Extract style for raised buttons (*)
  21336a5... stylesheet: Use toolbar style for header bars and action ba (*)
  f92e0ed... stylesheet: Reset toolbar styles for popovers (*)
  6502e96... stylesheet: Make GtkWindowControls buttons filled (*)
  2c0c15b... stylesheet: Make image buttons square (*)
  44dc0b3... stylesheet: Specificity bump for spinbutton buttons (*)
  be21dd5... view-switcher-button: Set spacing in css and match buttons (*)
  035456d... stylesheet: Add separator.spacer (*)
  2218040... doc: Mention the flat button changes in the migration guide (*)
  df50f94... example: Add a split button+button content page (*)
  62728c8... stylesheet: Make any arrow buttons and split buttons flat a (*)
  6fb3655... doc: Remove an outdated header bar split button mention (*)
  471d826... stylesheet: Support .image-button on menu buttons (*)
  886a4ee... doc: Fix typo in the migration guide (*)
  e947ca6... button-content: Don't expand icon when a label is visible (*)
  a4d1849... stylesheet: Fix menubutton.raised (*)
  a224568... stylesheet: Move needs-attention styles to _common.scss (*)
  907538f... stylesheet: Restrict .linked to box and grid (*)
  feeef12... stylesheet: Add .toggle-group style (*)
  76c0ebe... stylesheet: Use toggle group style for GtkStackSwitcher (*)
  fee4065... demo: Use .toggle-group instead of .linked for flap toggles (*)
  2967373... Add AdwSettings
  3c2b6c1... Add AdwStyleManager
  d0f6561... application: Proxy AdwStyleManager API
  d22d710... demo: Rework the dark mode button

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