Implemented the first route of the toResponse normalisationf for all classes

ref #67

src/models/entities/Track.ts

@@ -6,6 +6,7 @@ import {
   IsString
 } from "class-validator";
 import { Column, Entity, OneToMany, PrimaryGeneratedColumn } from "typeorm";
+import { ResponseTrack } from '../responses/ResponseTrack';
 import { ScanStation } from "./ScanStation";
 import { TrackScan } from "./TrackScan";
 
@@ -61,4 +62,11 @@ export class Track {
    */
   @OneToMany(() => TrackScan, scan => scan.track, { nullable: true })
   scans: TrackScan[];
+
+  /**
+   * Turns this entity into it's response class.
+   */
+  public toResponse(): ResponseTrack {
+    return new ResponseTrack(this);
+  }
 }