HighContrast and HighContrastInverse have been poorly supported in
this app for a long time because we ship many custom styles.

However, nowadays HighContrast and HighContrastInverse stylesheets
are derived from Adwaita stylesheet, so the same custom styles
can be applied cleanly. Let's do that.

Fixes https://gitlab.gnome.org/GNOME/nautilus/-/issues/1614
and fixes https://gitlab.gnome.org/GNOME/nautilus/-/issues/1469

The difference between @borders and @unfocused_borders colors is barely
noticeable with the regular stylesheet, but marked with high contrast.

When doing a DnD operation from outside Nautilus into one of
its windows, if the window is in "iconview mode", Nautilus
is able to detect when the origin and the destination folders
are in the same disk volume and do a move in that case, or
do a copy when they are in different volumes.

Unfortunately, when the window is in "treeview mode", this
operation doesn't work as expected, and always copy the file(s),
no matter if the origin and destination folders are or not in
the same volume.

After tracking the bug, I found that, in "treeview mode", the
NautilusFile object with the destination folder doesn't have
defined the filesystem_id property. This makes fail the
check_same_fs() function, which always returns FALSE. In
"iconview mode", instead, the object does have that property
defined, and that's why there it works.

I did a fix proposal, and although it was a safe workaround,
António Fernandes found a better way to fix it, which is
this patch.

Fix https://gitlab.gnome.org/GNOME/nautilus/-/issues/2170

This change only has an affect when nautilus is built without the libportal option

This matches the current behavior of xdg-desktop-portal-gnome

https://gitlab.gnome.org/GNOME/xdg-desktop-portal-gnome/-/commit/84f4f8619

We set a minimum width in characters for the labels in the pathbar not 
to collapse into a single ellipsis. Labels under this threshold are
excluded because in that case we just set them not to ellipsize and let
GtkLabel take care of the sizing.

However, the width in characters metric fails for variable-width fonts, 
such that in some cases we still set a wider label width than what the 
label text occupies.

So, raise the ellipsizing threshold further, and do it proportionally.

Fixes https://gitlab.gnome.org/GNOME/nautilus/-/issues/2202

(cherry picked from commit aa4a6a96)

Under X11, GTK3 cannot draw a GtkPopover outside of the main window area.

This means the popover for compress formats is clipped under X11.

As a workaround, make the window twice as tal when the popover is shown.

Fixes https://gitlab.gnome.org/GNOME/nautilus/-/issues/2018

(cherry picked from commit 203d24f1)

Currently, images with transparent backgrounds have their thumbnails
displayed with a white background image, which causes a visibility
issue for white images with no background in light mode.

Hence, a checkerboard background is added to the thumbnails of these
images, making them clearly visible.

Close https://gitlab.gnome.org/GNOME/nautilus/-/issues/2211

See gnome-desktop!132

Backported by António Fernandes <antoniof@gnome.org>

Fixes https://gitlab.gnome.org/GNOME/nautilus/-/issues/2201

GtkArrangement value is text-direction independant, apparently.

This reverts commit fbc9bd6f

The master branch introduces incompatible API changes in the
thumbnailing component.

The previously cherry-picked patch has been reverted because
it shouldn't have been applied to the stable branch.

Instead, in order to pass the pipeline, use stable dependency.

Fixes https://gitlab.gnome.org/GNOME/nautilus/-/issues/2237

Fix a mistake.