When spawning a new atril instance for cross-document links, the
destination and search parameters from the document were interpolated
directly into the command line without shell quoting. Values containing
spaces or special characters could be split into separate arguments by
the shell parser, potentially being interpreted as unintended flags by
the child process.

Apply shell quoting to page label, named destination, and search string
values before appending them to the command line, consistent with how
other spawn sites in the codebase already handle this.

Cairo surfaces have a limit of 32767px in any dimension, so we make sure
that we don't end up zooming in past the point where the rendered
surface is larger than that limit.

Measuring image dimensions based on rotation is unnecessary, since the
result is either w×h or h×w, which is commutative.

The EphyZoom widget uses logical zoom (eg. 100%)  while the libview widget uses
physical zoom, that is if logical zoom is 100% then scale will be 100%*dpi/72.0.

Backported from https://gitlab.gnome.org/GNOME/evince/-/commit/0a0a2d8c

shell: Add EvFindSidebar widget to show search results
see https://gitlab.gnome.org/GNOME/evince/-/commit/940ce8048e4fc6503dca03c1ce090ff4a11dface

eggfindbar: don't close the findbar when it loses the focus
see https://gitlab.gnome.org/GNOME/evince/-/commit/a2d781fb124bd19861035fd41dacc976e00d19ef

shell: Add the findbar to the main box instead of the view box

libview: Add ev_view_find_set_result

MATEDATADIR value is missing `prefix`, but is already properly defined
in the global C flags from the root meson.build, so we just need not to
override it incorrectly.

Also remove the LIBEXECDIR definition with is also wrong, but that is
not actually used.

A recent update to libwebkitgtk2gtk-4.1 breaks using WebKitWebView
in a GtkOffscreenWindow.

Disable the thumbnail sidebar with epub documents, and disable
updating the GtkWindow thumbnail.

ref:
https://github.com/WebKit/WebKit/commit/8d7385fad3ffb31d0c438e6b6a50dffb4390840c

Fixes: #631.

Signed-off-by: Oz Tiram <oz.tiram@gmail.com>