Updated fileName validation to allow spaces

Author: FrostyApeOne

src/DfE.ExternalApplications.Api/appsettings.json

@@ -83,7 +83,8 @@
       "AllowOverwrite": true,
       "MaxFileSizeBytes": 10000000,
       "AllowedExtensions": [ "jpg", "png", "pdf", "docx", "xlsx" ],
-      "AllowedFileNamePattern": "^[a-zA-Z0-9_-]+$"
+      "AllowedFileNamePattern": "^[\\sa-zA-Z0-9_-]+$",
+      "AllowedFileNamePatternFriendlyList": "a-z A-Z 0-9 _ - space"
     }
   },
   "NotificationService": {