Increase default limit on feed rate

There is no real limit by default now. Only light speed (and the limit on the input element's length). The feed rate limit should be set by a machine definition. If there is no limit set, let there be no limit to what the user can input.

Contributes to issue CURA-2284.

resources/definitions/fdmprinter.def.json

@@ -403,7 +403,7 @@
                     "description": "The maximum speed of the filament.",
                     "unit": "mm/s",
                     "type": "float",
-                    "default_value": 25,
+                    "default_value": 299792458000,
                     "settable_per_mesh": false,
                     "settable_per_extruder": false,
                     "settable_per_meshgroup": false

resources/definitions/ultimaker.def.json

@@ -9,6 +9,9 @@
         "visible": false
     },
     "overrides": {
+        "machine_max_feedrate_e": {
+            "default_value": 45
+        },
         "material_print_temperature": {
             "minimum_value": "0"
         },