Add asset repository and refactor asset service (#540)

* build endpoint to get asset count by month

* Added asset repository

* Added create asset

* get asset by device ID

* Added test for existing methods

* Refactor additional endpoint

* Refactor database api to get curated locations and curated objects

* Refactor get search properties

* Fixed cookies parsing for websocket

* Added API to get asset count by time group

* Remove unused code

mobile/openapi/lib/api_helper.dart

@@ -67,6 +67,9 @@ String parameterToString(dynamic value) {
   if (value is ThumbnailFormat) {
     return ThumbnailFormatTypeTransformer().encode(value).toString();
   }
+  if (value is TimeGroupEnum) {
+    return TimeGroupEnumTypeTransformer().encode(value).toString();
+  }
   return value.toString();
 }