added protected to and from json methods

OSI-API/Controllers/_EndpointBase.cs

@@ -1,6 +1,8 @@
 using System.Collections.Generic;
 using Microsoft.AspNetCore.Mvc;
 using System.Threading.Tasks;
+using System.Text.Json;
+using System.Text.Json.Serialization;
 
 namespace OSI.API.Controllers
 {
@@ -24,5 +26,30 @@ namespace OSI.API.Controllers
         // DELETE: api/Clients/5
         [HttpDelete("{id}")]
         public abstract IActionResult Delete(int id);
+
+        protected T FromJSON<T>(string input)
+        {
+            JsonSerializerOptions options = new()
+            {
+                Converters = {
+                   new JsonStringEnumConverter()
+               }
+            };
+
+            return JsonSerializer.Deserialize<T>(input, options);
+        }
+
+        protected string ToJSON<T>(T input)
+        {
+            JsonSerializerOptions options = new()
+            {
+                WriteIndented = true,
+                Converters = {
+                    new JsonStringEnumConverter()
+                }
+            };
+
+            return JsonSerializer.Serialize<T>(input, options);
+        }
     }
 }