SPHERE-1212 add new commands on Customer

3 new commands to update the customer.
- setCompanyName
- setVatId
- setDateOfBirth

For the last command I had to add a new Jackson serializer for the LocalDate type.
Why do we actually need to introduce the `companyName`, `vatId` and `dateOfBirth` in the `CreateCustomer` command? The backend API doesn't allow to add these fields on the Create Customer action, only on updating, so they are actually never used, are they?