(cherry picked from commit 938d7841833211824c64a4471e076f20d1187e81)

(cherry picked from commit 91d57ab9f26c3911146f76a1f9d4817a5ccf7b0b)

Improves the visual appearance of the Devtab Grid Toolbar by
making the toolbar a linked widget with the Devtab Grid above.
This prevents the odd visual look currently where the buttons in
the toolbar have squared-off corners on the insides, while
maintaining the UX-based separation of the 'delete-partition'
button (which is destructive) from the other buttons.

(cherry picked from commit e05beca11c9e445d0f19e04ce15ef86e61ba35d7)

No specific ToolButton api was used and they are defined as Buttons in
the UI.

Those constants are gone in GTK 4.

The former is deprecated.

A pack_type end was removed intentionally.

(cherry picked from commit 2160028c6a4a8352b4bda4488ddfc0d3fe8d5952)

(cherry picked from commit bbd2fecb405b314c9662212dd9284eb44e68c54d)

It's in the sdk.

Bump minimum libhandy version to 1.5.0; use a slightly newer commit for the
subproject to include https://gitlab.gnome.org/GNOME/libhandy/-/merge_requests/793

`i18n.merge_file` has been ignoring positional arguments for a time
and explicitly rejects with error since meson 0.60.0

The refactor in ff4c7021
used an early destruction of the dialog window which caused the
retrieval of the combo box value to fail.

Restore the old flow of hiding the window only and let the
destruction be done by the format_disk_data_free call.

Fixes https://gitlab.gnome.org/GNOME/gnome-disk-utility/-/issues/238

(cherry picked from commit ab6f23d9ee7eaed94041d51694d986838ce6cc7d)

(cherry picked from commit dd25032fb759b33ef7b0b4e08234b4dbf903333b)