Make things more consistent in dark; fix dialog dimming in both.

Introduce @sidebar_border_color and @secondary_sidebar_border_color since
those shade colors were used basically because they just happened to work
with the old values.

Fix inaccuracies wrt sidebar shade colors: the additional listed
requirement for border colors was always there, that's in fact why the new
colors were needed in the first place.

See https://gitlab.gnome.org/GNOME/libadwaita/-/issues/809#note_2019858

Otherwise either we take over everything incl. buttons, or window handle
takes over.

More specifically, make close button in dialogs work on touch.

Otherwise we can very easily end up with duplicate ::closing emissions,
which breaks everything.

Instead, ensure the natural width never gets smaller than that.

Setting "child" via `adw_status_page_set_child()` should notify for
`PROP_CHILD`, not `PROP_DESCRIPTION`.

Fixes https://gitlab.gnome.org/GNOME/libadwaita/-/issues/810

The `adw_navigation_view_push...()` functions emit a `::pushed` signal,
not a `::popped` signal.

Fix this typo in the docs.

Similar to what was done in GTK4

Update to upstream version '1.5~rc'
with Debian dir a0055d0b

tagging package libadwaita-1 version debian/1.5_rc-1

* tag 'debian/1.5_rc-1': (60 commits)
  releasing package libadwaita-1 version 1.5~rc-1
  Revert 3 commits bumping minimum GTK4
  New upstream release
  Release 1.5.rc
  Update Russian translation
  Update Polish translation
  Update Korean translation
  Update Hungarian translation
  Update Basque translation
  toolbar-view: Properly link to #undershoot-indicators
  Add Latvian translation
  Update Hebrew translation
  Updated Spanish translation
  Update British English translation
  Update Catalan translation
  Set LIBGL_ALWAYS_SOFTWARE=true in autopkgtests instead of allow-stderr
  navigation-view: Disable missing title warning for split views
  Update Chinese (China) translation
  Update Indonesian translation
  Update Persian translation
  ...