enableUuidHack required for query relations to load when relation keys are uuids

[calvin-cdev]

Package versions and database engine type (please complete the following information):

• Database Engine: postgres
• TypeORM Version: 0.2.41
• Driver Version: 2.3.5

Describe the bug
When you have a repository query that uses the relation option to load related entities where the relation relies on a uuid field, the query will fail unless enableUuidHack is set to true

You'll get

BadRequestException: ERROR: operator does not exist: uuid = character varying

Presumably because the ids on the relations are not casted a uuid

To Reproduce

@Entity()
export default class A {
  @PrimaryGeneratedColumn('uuid')
  id: string;

  @Column()
  name: string

  @Column()
  bId: string;

  @ManyToOne(() => B)
  @JoinColumn({ name: 'bId' })
  b: B;
}

@Entity()
export default class B {
  @PrimaryGeneratedColumn('uuid')
  id: string;

  @OneToMany(() => A, a => a.b)
  a: Array<A>;
}

// create connection without passing `formatOptions` (i.e. enableUuidHack is false)
createConnection({
    type: 'aurora-data-api-pg',
    database: '...',
    secretArn:'...',
    region: '...',
    entities: [
      A,
      B
    ],
  });

// A custom repo
@EntityRepository(A)
export class ARepository extends Repository<A> {
  findByName(
    name: A['name'],
  ): Promise<A | undefined> {
    return this.findOne({
      where: { name },
      relations: ['b'],
    });
  }
}


// use the repo method, it will fail with 
// BadRequestException: ERROR: operator does not exist: uuid = character varying
const result = await getCustomRepository(ARepository).findByName('a name')