Add sql connection string to response List SQL Endpoints api call

[AD_21]

The sql endpoint api (/workspaces/{workspaceId}/sqlEndpoints) responds with 

{ "value": [ { "id": "3546052c-ae64-4526-b1a8-52af7761426f", "displayName": "SQLEndpoint Name 1", "description": "A SQL endpoint description.", "type": "SQLEndpoint", "workspaceId": "cfafbeb1-8037-4d0c-896e-a46fb27ff229" } ] }

It would be very helpfull if the sql connections string of that endpoints would also be included in the response so that it can be used in other processes.