User => Adapt interface to new db schema

models/User.ts

+import UserRole      from './UserRole';
+import Exercise      from './Exercise';
+import Assignment    from './Assignment';
+import GitlabProfile from '../../shared/types/Gitlab/GitlabProfile';
+
+
 interface User {
     id: number;
-    firstName: string;
-    lastName: string;
+    name: string;
     mail: string;
-    gitlabId: number;
-    role: string;
+    role: UserRole;
+    gitlabUsername: string;
+    gitlabLastInfo: GitlabProfile;
     isTeachingStaff: boolean;
+    isAdmin: boolean;
     deleted: boolean;
+
+    assignments?: Array<Assignment>;
+    exercises?: Array<Exercise>;
 }