Management API model mapping take two (#15667)

* Re-modelling API models (take two)

* Do not use "content" - use "document" and "media" instead.

* Move "item" endpoints to their own silo

* Use "Id", not "Key"

* Regenerate OpenApi.json

* Rename user start node IDs from "content" to "document"

* Regererate OpenApi.json after forward merge

* update importmap

---------

Co-authored-by: Mads Rasmussen <madsr@hey.com>

src/Umbraco.Cms.Api.Management/ViewModels/User/ResendInviteUserRequestModel.cs

@@ -1,11 +1,8 @@
-using System.ComponentModel.DataAnnotations;
-
 namespace Umbraco.Cms.Api.Management.ViewModels.User;
 
 public class ResendInviteUserRequestModel
 {
-    [Required]
-    public Guid UserId { get; set; } = Guid.Empty;
+    public required ReferenceByIdModel User { get; set; }
 
     public string? Message { get; set; }
 }