update Snapmaker profiles

- add Breakaway Support filament
- add preheat params for Snapmaker Dual/IDEX printers
- update the check bounds code in start-gcode, which is now off by default

resources/profiles/Snapmaker/machine/fdm_linear2_dual.json

@@ -21,5 +21,9 @@
   "default_filament_profile": [
     "Snapmaker PLA",
     "Snapmaker PETG"
+  ],
+  "extruder_offset": [
+    "0x0",
+    "0x0"
   ]
 }