Update German translation

See merge request Librem5/phosh!94

phosh: Scale monitor resolution

Closes #30

See merge request Librem5/phosh!93

wl_output gives us the unscaled resolution. We need to scale that with
the currently set scale. This brings the settings menu back to the
screen and makes the favorites menu fit.

Also take the home buttons size into account and flip width and height
on rotation.

Closes: #30

Take screenshots during CI

See merge request Librem5/phosh!92

We're only interested in phosh's criticals and warnings so adjust
the corresponding greps.

implement system prompter

Closes #19

See merge request Librem5/phosh!67

This gives us system modal dialogs for all important pin entries (if
they use Gcr as they should).

Based on gnome-shell's shell-keyring-prompt.c as well as Gcr's
own ui/gcr-prompt-dialog.c

Closes: #19

This makes e.g. gcr system prompter happy but other things like
services trying to connect to g-s-d need it too.

This should increase readability and make it simpler for folks not
familiar with the script.

settings: Make brightness slider work correctly

See merge request Librem5/phosh!90

Clicking on the slider worked but dragging it resulted in a flickering
display. This works now but beware of

    https://github.com/swaywm/wlroots/issues/613

Start phosh via gnome-session

Closes #23

See merge request Librem5/phosh!83

This is not good for the running session.

Things like gnome-terminal require an UTF-8 locale and although we
expect gnome-session to set this up it's better to have a UTF-8 locale
right away.

This makes sure other packaging formats get the configuration too.

Phosh is of little use without it.

Instead of launching rootston directly spawn it via /usr/bin/phosh and
make it run the session.

Closes: #23

Install it to /usr/share/gnome-session/ so GNOME's gnome-session
can find it.

gnome-session starts applications by desktop file.

We set X-GNOME-AutoRestart=false for the moment to make it simpler to
spawn new development versions. We might change that at a later point
for release builds.

gnome-session needs an X11 display so start rootston first and make it
spawn gnome-session (which will spawn phosh later on).

Preface all LayerSurface namespaces with "phosh"

See merge request Librem5/phosh!89

This makes sure our rootston extension can find it. Name the panel
itself "phosh" since this surface's output is being rotated.

Add home button

Closes #27

See merge request Librem5/phosh!88

Just the button to spawn the favorites. Favorites, top anel rework will
be done separately (See #24, #29)

Closes: #27

The convention is to have the _TYPE_ after the prefix

Turn panel into a PhoshLayerSurface instead of open coding it

Closes #21

See merge request Librem5/phosh!87

Closes: #21

Introduce PhoshLockscreenManager

Closes #25

See merge request Librem5/phosh!85

This makes it configurabe via gnome-settings. But see #28 where this has
to go.