Extend MetaFrameBorders to include shadow and resize borders to
calculate invisible border size. Also added border caching to prevent
recalculating borders on every frame operation.

This is a backport of the following commits from Metacity:
- https://gitlab.gnome.org/GNOME/metacity/-/commit/21e664af
- https://gitlab.gnome.org/GNOME/metacity/-/commit/3c6e269b
- https://gitlab.gnome.org/GNOME/metacity/-/commit/700e87ea

When calculating the clickable area on the left-most button of
a maximized window, we need to take into account the layout components,
not just the button size.

Fixes mate-desktop/mate-themes#318

Apply Fitt's law to corner window buttons by extending the clickable
area all the way to the edge of the screen on maximized/tiled windows.
This means that a user moving the pointer all the way to the top-right
corner and clicking, will close the maximized (or right-tiled) window.
The same applies for top-left on maximized and left-tiled windows.

* menu: replace gtk_menu_popup() with gtk_menu_popup_at_rect()

Replace deprecated gtk_menu_popup() with gtk_menu_popup_at_rect(). This
provides the same menu positioning calculation while eliminating
deprecation warnings.

* ui: replace gtk_widget_get_realized() with gtk_widget_get_mapped()

Replace deprecated gtk_widget_get_realized() with
gtk_widget_get_mapped(). Since mapped widgets are guaranteed to be
realized, and we only care about widget visibility, this change
eliminates deprecation warnings while maintaining the same
functionality.

* frames: replace gdk_window_process_all_updates() with gdk_display_flush()

Replace deprecated gdk_window_process_all_updates() with
gdk_display_flush(). Both functions ensure pending updates are
processed, but gdk_display_flush is more general for all display
requests.

In systems with bamfdaemon running, windows get this property for
finding the dekstop spec file of an application. This can be used to
find the defined icon for any application window that reports this
attribute and provider much better icon matching.

Looking up GDesktopAppInfo from the GTK Application ID we can get a much
better match for the icon and load it at the appropriate scale. This
results in matching icons to straneous windows and better looking icons
overall.

The switcher windows aren't actually "active" per GTK's meaning because
they do not have actual keyboard focus, but they are controlled by the
internal grabs so it's effectively the same as if they were active.

Reporting them as such helps the ATs understanding what's going on.

Fixes #771.

When composited, the tab popup uses an OSD style which typically has a
dark background, so we use a light background highlight color.
However, when not composited the popup uses a light color and should
thus use a dark highlight.  This was done for the workspace popup, but
not for the window one, leading to the highlight being hardly visible
in several themes.