Customer Microservice Strucutre & DTO & DDBB

Create package strucutre of microservice packages & CustomerDTO & DDBB

PACKAGES:
- Controller
- Service
- Repository
- DTO
- Utilities
- Exceptions
- Documents / Entities
- Helpers

FIELDS OF "CustomerDTO":
- Id => UUID
- Name => String
- DNI => String
- Address => AddressDTO
- Orders List => List

FIELDS OF "AddressDTO":
- Stret => String
- City => String
- Postal Code => int
- Country => String

METHOD CHECK DNI:
- Method to check correct DNI strucuture