Closes: #1019315

We used to select the first search result as soon as it arives,
in order to allow keyboard shortcuts to take effect on it. This
makes search more efficient to use with keyboard.

Prior to the gtk4 port (and the introduction of list-base,
canvas view and list view set the selection directly in `select_first`
through `icon_set_selected` and `gtk_tree_selection_select_iter`.

After the port to gtk4, list-base used the existing function
`nautilus_view_set_selection` which seemed to work, except
`nautilus_files_view_set_selection` only actually sets the selection
when the view is not loading.  In the meantime, it puts the selection
is a pending_selection to be set when the loading is complete.

This causes problems for search because loading generally takes
longer to complete in a search, and the user will have to wait
until the search is complete for the item to be selected.
As a matter of fact, the *only* time that select_first is used
is during a search (which was the original intention of the function
when introduced in 50711e28).

There's no need to add further complexity, beyond what the
GtkSelectionModel already provides.  Just as `real_select_all`
simples calls `gtk_selection_model_select_all`, make
`real_select_first` call `gtk_selection_model_select_item`.

Fixes: https://gitlab.gnome.org/GNOME/nautilus/-/issues/2481

During the switch to GTK4 (e358c234), nautilus-x-content-bar
parent was changed from GtkInfoBar to AdwBin, but the G_DEFINE_TYPE
macro wasn't updated accordingly.

Fixes: https://gitlab.gnome.org/GNOME/nautilus/-/issues/2477

Update to upstream version '43.0'
with Debian dir 65c79b8343c0dee80442ced7f4b095d4668516c1

tagging package nautilus version debian/43.0-1