* GtkBox isn't meant to be subclassed, and apps should not do it.
Instead they should subclass AdwBin or GtkWidget depending on their
use case.

* The main reason we were using GtkBox was to contain our header
and our content. Now we use AdwToolbarView for that purpose.

This only leaves us with only one translatable string defined on a rust file,
due to the low gettext/rust support...

It is nowadays similar to the ImagePageWidget, so let us just use that

Instead of doing multiple overlays, do a single overlay containing all
buttons as type=overlay children. This makes the carousel span the
window from start to end.

This allow us to simplify the changes on the UI part

it doesn't make much sense now, but it will do once we port the rest of widgets as well

* .page-body is indistinguishable from the default body style
* libadwaita uses .title-1, so .page-title can be swapped out
* .large-title was unused
* Other empty styles removed

The defaults work fine.

This commit upgrades our rust dependencies and ports
Tour to libadwaita+GTK4. As part of porting we now use
GtkPicture instead of GtkImage, and AdwClamps to hold pages
in place.

This port is part of https://gitlab.gnome.org/GNOME/Initiatives/-/issues/26 and handles https://gitlab.gnome.org/GNOME/Initiatives/-/issues/32

Fixes https://gitlab.gnome.org/GNOME/gnome-tour/-/issues/36

fixes https://gitlab.gnome.org/GNOME/gnome-tour/-/issues/45

- clean up unused pages
- add keyboard overview
- add search
- reword

Fixes https://gitlab.gnome.org/GNOME/gnome-tour/-/issues/41
Fixes https://gitlab.gnome.org/GNOME/gnome-tour/-/issues/42

tweak super key illustration

tweak super key illustration

- more of an adventure tour vibe

- avoid baloon duplicty

as the 'close' button is smaller, there's a weird
allocation thing when going from page 1 to page 2 for the first time

- make rocket more visible

- Fullcolor tour
- Basic CSS keyframe animations
- Use of default grey backgrounds due to headerbar

Fixes https://gitlab.gnome.org/GNOME/gnome-tour/-/issues/29

600x300px

you should be able to configure the video path at build
time by passing --video_path=absolute_path
which will be played instead of displaying the LOGO

- get rid of the purple. The joys of a colorblind designer

addresses concern https://gitlab.gnome.org/GNOME/gnome-tour/-/issues/17#note_886067

- align Software icon
- adjust grid position and alignment
- replace some app icons

See https://gitlab.gnome.org/GNOME/gnome-tour/-/issues/17

- Add dropshadow for the Software icon, replace Banner viewer with
  Foliate

Based on design review https://gitlab.gnome.org/GNOME/gnome-tour/-/issues/17