refactor: promote DevAmsType to global enum, rename DUMMY to EXT_SPOOL

Matches BambuStudio's DevAmsType naming convention.

src/slic3r/GUI/DeviceCore/DevDefs.h

@@ -40,6 +40,15 @@ enum AmsStatusMain
     AMS_STATUS_MAIN_UNKNOWN = 0xFF,
 };
 
+enum DevAmsType : int
+{
+    EXT_SPOOL = 0,      // EXT
+    AMS = 1,            // AMS1
+    AMS_LITE = 2,       // AMS-Lite
+    N3F = 3,            // N3F, AMS 2PRO
+    N3S = 4,            // N3S, AMS HT
+};
+
 // Slots and Tray
 #define VIRTUAL_TRAY_MAIN_ID    255
 #define VIRTUAL_TRAY_DEPUTY_ID  254