window: only allocate the needed width of title widget

The title widget is switched out using a stack, with a
Gtk.Stack for hhomogeneous having a default value of true.

Thus, each possible title widget is allocated the same
width, and the vertical view is constrained by the width
of the language selector even if the "Dialect" string is
visible.

With a longer translation of "Auto" and/or a non-default
window button layout with at least one on the left or at
least two on the right, this results in the window not
being able to shrink down to 360px.

Signed-off-by: Markus Göllnitz <[email protected]>

data/resources/window.blp

@@ -248,6 +248,7 @@ template $DialectWindow : Adw.ApplicationWindow {
             centering-policy: strict;
             title-widget: Stack title_stack {
               transition-type: crossfade;
+              hhomogeneous: false;
 
               StackPage {
                 name: "selector";