Added error message to validate connect params. (#1660)

* Added error message to validate connect params.

* removed connectionParam == null as ConnnectionCompleteParams cannot be nulled.

* Added ValidateConnectParams to other connection services

* removed message from error

* reverted change to connectionServiceCore

* added updated message

* restore null and added errormessage to GetConnectionCompleteParams

* fix for sr.xlf

* fix for tab

* another fix to tabs

* added message to connection complete error

* small fix

src/Microsoft.Kusto.ServiceLayer/Connection/ConnectionService.cs

@@ -139,7 +139,7 @@ namespace Microsoft.Kusto.ServiceLayer.Connection
                 return new ConnectionCompleteParams
                 {
                     OwnerUri = connectionParams.OwnerUri,
-                    Messages = paramValidationErrorMessage
+                    ErrorMessage = paramValidationErrorMessage,
                 };
             }
 
@@ -371,6 +371,7 @@ namespace Microsoft.Kusto.ServiceLayer.Connection
             catch (Exception ex)
             {
                 response.Messages = ex.ToString();
+                response.ErrorMessage = ex.Message;
             }
 
             return response;