filechoosernativeportal: Allowing selecting folder(s)

See merge request !1523

Adwaita: work around holes in unfocused windows

See merge request !1574

- works around holes in rounded corners of backdrop windows

Fixes #2537

Translate geometry with offscreen windows

See merge request !1566

offscreen windows return NULL for its parent

Suggested in !1503

Use the "directory" portal option when asked to select folders.

Add gtk_get_portal_interface_version() to check the version of a portal.

If the version can't be fetched, don't throw a warning.

Rather than open coding it.

Define begin_move_drag for GdkOffScreenWindow

See merge request !1548

Avoid crashes calling it on drag and drop gestures

fixes #2532

theme: use tabular figures where appropriate

See merge request !1493

Fix crash with certain IME

See merge request !1290

GTK3: short-circuit char visibility check when possible

See merge request !1536

If we have never seen a GtkTextTag in the GtkTextTagTable with the
invisible bit set, then we do not need to go through the process of
checking the accumulated tags.

Not using invisible tags is overwhelmingly the common case.

This avoids looking up the signal by name and instead uses the saved
signal identifier from gtktexttagtable.c

This makes backporting changes from 4.x a bit easier.

imwayland: Fix typo in code

See merge request !1533

To find the middle of the string, we should check both cursor/anchor.
This is actually a backport of commit 8fc360da in master.

Closes: #2522

- unescape variables (gtk3 didn't raise warnings like gtk4, but it was broken)

- lighten up radios, switches and checkboxes

Fixes #2461

imwayland: Honour len argument in gtk_im_context_wayland_set_surrounding

See merge request !1528

Clients may pass not `NULL`-terminated strings as the function takes a
`len` argument. Use that argument.

document font-feature-settings CSS property

See merge request !1483

Update the CI pipeline for GTK3

See merge request !1508

Skip just the failing tests in release builds.

Some tests are expected to fail.

Some tests are expected to fail in non-debugging builds.

The icontheme test is the latter.

GCC complains with boxed out arguments that may be unset.

Declare debug-only variables inside a G_ENABLE_DEBUG conditional block.

Don't use `if`, as we don't unconditionally define the symbol.