web/TransferSettings: friendlier error messages

web/i18n/en/error.json

@@ -0,0 +1,5 @@
+{
+    "import.no_data": "there's nothing to load from the file. are you sure it's the right one?",
+    "import.invalid": "your file doesn't have valid cobalt settings to import. are you sure it's the right one?",
+    "import.unknown": "couldn't load data from the file. it may be corrupted or of wrong format. here's the error i got:\n{{ value }}"
+}