[feature]: Add work item custom properties to /work-items/ API response

Is there an existing issue for this? • I have searched the existing issues Summary I have created some custom work item properties so that I can leverage them via some automated processes. However, I've just discovered the number of steps it takes with different API endpoints just to retrieve a single custom property value. If I have this wrong and there's a better way to do it, I'm all ears 1. Call list all work items API 2. For each work item, use the work item type Id to call the List custom properties endpoint 3. For each custom property, call the custom property values endpoint to retrieve the value So let's say for example I have a work item type with 2 custom properties. That means if I want to retrieve the "standard" properties as well as the custom ones for a single work item, I have to make 4 separate API calls to retrieve that value 1. GET /work-items 2. GET /work-item-types/{type_id}/work-item-properties 3. GET /work-item-properti…