More advanced pause tweaks (#12356)

* Followup to LCD_TIMEOUT_TO_STATUS=0
* Make continuous purge screen fit 20x4
* Unify purge message modes
* Preserve last-set pause header mode

Marlin/src/lcd/menu/menu_delta_calibrate.cpp

@@ -50,7 +50,7 @@ void _man_probe_pt(const float &rx, const float &ry) {
   float lcd_probe_pt(const float &rx, const float &ry) {
     _man_probe_pt(rx, ry);
     KEEPALIVE_STATE(PAUSED_FOR_USER);
-    defer_return_to_status = true;
+    set_defer_return_to_status(true);
     wait_for_user = true;
     while (wait_for_user) idle();
     KEEPALIVE_STATE(IN_HANDLER);