inspector: Make picking objects show them

Changing the selection in the object tree is
not a useful action if we are already in the
object details. Most likely, a user who picks
an object wants to inspect its details, so
just always show them.

Fixes: #1876

gtk/inspector/inspect-button.c

@@ -92,7 +92,7 @@ select_widget (GtkInspectorWindow *iw,
 {
   GtkInspectorObjectTree *wt = GTK_INSPECTOR_OBJECT_TREE (iw->object_tree);
 
-  gtk_inspector_object_tree_select_object (wt, G_OBJECT (widget));
+  gtk_inspector_object_tree_activate_object (wt, G_OBJECT (widget));
 }
 
 static void