Create endpoint to upload documents and add ability to attach uploaded documents to records.

Models/GasRecord/GasRecordViewModel.cs

@@ -23,6 +23,7 @@
         public string Notes { get; set; }
         public List<string> Tags { get; set; } = new List<string>();
         public List<ExtraField> ExtraFields { get; set; } = new List<ExtraField>();
+        public List<UploadedFiles> Files { get; set; } = new List<UploadedFiles>();
         public bool IncludeInAverage { get { return MilesPerGallon > 0 || (!IsFillToFull && !MissedFuelUp); } }
     }
 }