[Search] Allow Searching in nested ORM\Embedded property

[gmorel]

Pain Point

Thanks to #3864 you can now search on nested entities :rocket:. But if you try to search on an Entity which has nested Embedable you might have this error

CRUD config:

Usecase:

• property (ORM\ManyToOne)
  • landlord (ORM\ManyToOne)
    • person1 (ORM\Embedded)
      • firstName (string)

It fails to find person1 since only person1.firstName is mapped in landlord.

TODO

• [x] Allow searching on nested embeddable
• [ ] Unit Test

[gmorel]

I wanted to unit test it. But EntityRepository is not tested yet.