Bypass the threaded EvJobFind for EPUB documents and use WebKit's
WebKitFindController directly. The threaded find job was incompatible
with GepubDoc's single-threaded design and caused segfaults. The new
approach searches within the current page using WebKit's built-in text
search and highlighting, which is both simpler and thread-safe.

Assisted-by: OpenCode:claude-opus-4-6

The sidebar settings were ignored when opening documents on systems
without GVFS metadata support.

Now when metadata is not available, we use whatever is in gsettings, and
when metadata is available, we respect the per-document state.

Fixes #163

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

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.

ev_document_model_get_page_layout ...

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