move generic models and DTOs to the root folder and split waypoint and coordinate

src/airport/models/arrivalroute.model.ts

@@ -1,7 +1,7 @@
 import { Prop, Schema, SchemaFactory } from '@nestjs/mongoose';
 import { Document } from 'mongoose';
 import { Constraint, ConstraintSchema } from './constraint.model';
-import { Waypoint, WaypointSchema } from './waypoint.model';
+import { Waypoint, WaypointSchema } from '../../models/waypoint.model';
 
 export type ArrivalRouteDocument = ArrivalRoute & Document;