Serial and pins debug cleanup

- Rename some AVR / DUE / ESP32 serial types
- Reduce two #error to one static_assert
- Update AVR/DUE error messages

Marlin/src/HAL/DUE/MarlinSerialUSB.h

@@ -27,11 +27,9 @@
  */
 
 #include "../../inc/MarlinConfig.h"
-#if HAS_USB_SERIAL
-
-#include <WString.h>
 #include "../../core/serial_hook.h"
 
+#include <WString.h>
 
 struct MarlinSerialUSB {
   void begin(const long);
@@ -50,14 +48,14 @@ struct MarlinSerialUSB {
     FORCE_INLINE int rxMaxEnqueued() { return 0; }
   #endif
 };
-typedef Serial1Class<MarlinSerialUSB> MSerialT;
 
 #if SERIAL_PORT == -1
-  extern MSerialT customizedSerial1;
+  typedef Serial1Class<MarlinSerialUSB> MSerialT1;
+  extern MSerialT1 customizedSerial1;
 #endif
 
 #if SERIAL_PORT_2 == -1
-  extern MSerialT customizedSerial2;
+  typedef Serial1Class<MarlinSerialUSB> MSerialT2;
+  extern MSerialT2 customizedSerial2;
 #endif
 
-#endif // HAS_USB_SERIAL