add display for sub projects

src/Project/Controllers/SubProjectController.cs

-using Coscine.Action;
-using Coscine.Action.EventArgs;
-using Coscine.Action.Implementations.Project;
-using Coscine.Api.Project.Models;
+using Coscine.Api.Project.Models;
 using Coscine.Api.Project.ReturnObjects;
 using Coscine.ApiCommons;
-using Coscine.ApiCommons.Exceptions;
-using Coscine.ApiCommons.Factories;
 using Microsoft.AspNetCore.Mvc;
-using Microsoft.SharePoint;
 using System;
-using System.Collections.Generic;
 using System.Linq;
 
 namespace Coscine.Api.Project.Controllers
 {
-    class SubProjectController : Controller
+    public class SubProjectController : Controller
     {
         private readonly Authenticator _authenticator;
-        private readonly List<IProjectAction> projectActions;
 
-        [Route("[controller]/{parentId}")]
+        public SubProjectController()
+        {
+            _authenticator = new Authenticator(this, Program.Configuration);
+        }
+
+        [HttpGet("[controller]/{parentId}")]
         public IActionResult Get(string parentId)
         {
             Guid parentGuid = new Guid(parentId);
             return Ok(_authenticator.ValidateAndExecute((user) =>
             {
                 ProjectModel projectModel = new ProjectModel();
-                Database.Model.Project ob = projectModel.GetById(parentGuid);
+                SubProjectModel subProjectModel = new SubProjectModel();
 
-                return projectModel.GetAllWhere((project) =>
-                    (from subProject in project.SubProjectsProjectIdIds
-                     where subProject.ProjectId == parentGuid select subProject).Any()
-                ).Select((project) => new ProjectObject(project.Id, project.Description, project.DisplayName, project.Organization, project.StartDate, project.EndDate, project.Keywords, parentGuid));
+                var subProjects = subProjectModel.GetAllWhere((subProjectM) => (subProjectM.ProjectId == parentGuid))
+                                                 .Select((subProject) => projectModel.GetById(subProject.SubProjectId))
+                                                 .Select((project) => new ProjectObject(project.Id, project.Description, project.DisplayName, project.Organization, project.StartDate, project.EndDate, project.Keywords, parentGuid));
+                return subProjects;
             }));
         }
     }

src/Project/Models/SubProjectModel.cs

 using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Linq.Expressions;
-using Coscine.Api.Project.ReturnObjects;
 using Coscine.ApiCommons.Models;
 using Coscine.Database.Model;
 using LinqToDB;
 
 namespace Coscine.Api.Project.Models
 {
-    public class SubProjectModel : DatabaseModel<Coscine.Database.Model.SubProject>
+    public class SubProjectModel : DatabaseModel<SubProject>
     {
         public SubProjectModel() : base(Program.Configuration)
         {
@@ -28,13 +25,11 @@ namespace Coscine.Api.Project.Models
 
         public void LinkSubProject(Guid parentId, Guid childId)
         {
-            Coscine.Database.Model.SubProject subProject = new Coscine.Database.Model.SubProject()
+            Insert(new SubProject()
             {
                 ProjectId = parentId,
                 SubProjectId = childId,
-            };
-            Insert(subProject);
-            return;
+            });
         }
 
         public override void SetObjectId(SubProject databaseObject, Guid id)