Fix [change_theme] requiring a separate action to refresh the UI afterwards

This also makes it so the status panels are updated immediately.

(cherry picked from commit 84fef75235)

changelog.md

@@ -54,6 +54,9 @@
  ### Miscellaneous and bug fixes
    * Rest healing now happens on turn 2. (issue #3562)
    * Normal healing now happens on turn 1 for all sides except the first. (issue #3562)
+   * [change_theme] no longer requires running a separate action to update the
+     UI afterwards (e.g. [redraw]) and the status panels are updated immediately.
+     as well.
 
 ## Version 1.14.5+dev
  ### Campaigns

src/display.cpp

@@ -266,6 +266,7 @@ void display::set_theme(config theme_cfg) {
 	action_buttons_.clear();
 	create_buttons();
 	invalidate_theme();
+	redraw_everything();
 }
 
 void display::init_flags() {