Laser Coolant Flow Meter / Safety Shutdown (#21431)

Co-authored-by: Scott Lahteine <thinkyhead@users.noreply.github.com>

Marlin/src/lcd/marlinui.h

@@ -43,6 +43,10 @@
   #define HAS_ENCODER_ACTION 1
 #endif
 
+#if HAS_STATUS_MESSAGE
+  #define START_OF_UTF8_CHAR(C) (((C) & 0xC0u) != 0x80U)
+#endif
+
 #if E_MANUAL > 1
   #define MULTI_MANUAL 1
 #endif
@@ -311,6 +315,7 @@ public:
     static void abort_print();
     static void pause_print();
     static void resume_print();
+    static void flow_fault();
 
     #if HAS_WIRED_LCD