feat(train-sets): implement multi-locomotive support for train sets

- Added TrainSetLocomotive entity to link multiple locomotives to a train set.
- Updated TrainSet entity to include a OneToMany relationship with TrainSetLocomotive.
- Modified the train scheduling logic to require at least two locomotives for a train set.
- Enhanced the UI components to support selecting multiple locomotives.
- Introduced new permissions for viewing customs clearance.
- Updated migrations to create the train_set_locomotives table and backfill existing data.
- Implemented utility functions for managing train numbers based on cargo type and direction.
- Added tests for train number utilities to ensure correct functionality.

apps/edr-freight-api/src/modules/train-sets/train-sets.module.ts

@@ -2,12 +2,13 @@ import { Module } from '@nestjs/common';
 import { TypeOrmModule } from '@nestjs/typeorm';
 
 import { TrainSet } from './entities/train-set.entity';
+import { TrainSetLocomotive } from './entities/train-set-locomotive.entity';
 import { TrainSetWagon } from './entities/train-set-wagon.entity';
 import { TrainSetWagonsRepository } from './train-set-wagons.repository';
 import { TrainSetsRepository } from './train-sets.repository';
 
 @Module({
-  imports: [TypeOrmModule.forFeature([TrainSet, TrainSetWagon])],
+  imports: [TypeOrmModule.forFeature([TrainSet, TrainSetWagon, TrainSetLocomotive])],
   providers: [TrainSetsRepository, TrainSetWagonsRepository],
   exports: [TrainSetsRepository, TrainSetWagonsRepository],
 })