adding string limits for billing address

@odorcicd @bslobodin 
https://pagseguro.uol.com.br/v2/guia-de-integracao/api-de-pagamentos.html

This adds a list of limits for the strings send to PagSeguro. If present, I just slice it. If the string is too big, PagSeguro explodes. ¬¬
From PagSeguro docs:

> HTTP parameter: 
shippingAddressCountry 

> Informs the country of shipping address product. This field is optional and you can send it if you have already captured the buyer data in your system and want to prevent it meets these data again in PagSeguro. 

> Attendance: Optional. 
Type: Text. 
Format: At the moment, only the BRA value is allowed.

Should we leave this dynamic as we always pass `BRA` to it?