Fix getDefine return null if there are multiple defines

Fix Parameterdescription is not part of SupportedParameters some times

Author: patrick-dmxc

RDMSharp/Metadata/MetadataFactory.cs

@@ -295,6 +295,8 @@ private static MetadataJSONObjectDefine getDefine(ParameterBag parameter)
                 if (parameter.DeviceModelID != null)
                 {
                     possibleDefines = possibleDefines.Where(d => d.DeviceModelID == parameter.DeviceModelID).ToList();
+                    if (possibleDefines.Count == 0)
+                        return define;
                     if (possibleDefines.Count == 1)
                         define = possibleDefines[0];
                     else if (possibleDefines.Count > 1)

RDMSharp/RDM/Device/RDMDeviceModel.cs

@@ -220,6 +220,9 @@ private async Task requestSupportedParameters()
                 if (DeviceInfo.Dmx512CurrentPersonality.HasValue) // Remote Device not send DMX_PERSONALITY Parameter but uses it!
                     supportedParameters.TryAdd(ERDM_Parameter.DMX_PERSONALITY, true);
 
+                if (!this.supportedParameters.ContainsKey(ERDM_Parameter.PARAMETER_DESCRIPTION) && this.supportedParameters.Any(p=> ((ushort)p.Key) >= 0x8000 && ((ushort)p.Key) >= 0xFFDF)) // Remote Device not send PARAMETER_DESCRIPTION Parameter but has Manufacture speific Parameters it!
+                    this.supportedParameters.TryAdd(ERDM_Parameter.PARAMETER_DESCRIPTION, true);
+
                 if (!this.supportedParameters.ContainsKey(ERDM_Parameter.IDENTIFY_DEVICE)) //Test it if the device supports Identify Device Parameter, if not it will be labled as not supported later on
                     this.supportedParameters.TryAdd(ERDM_Parameter.IDENTIFY_DEVICE, true);