Add Contact Information request object

[richherrera]

Summary of changes

Introduces support for passing recipient contact information in the BTPayPalCheckoutRequest

• A new class BTContactInformation was created to encapsulate the recipient's contact information for the order.
  Properties: recipientEmail andrecipientPhoneNumber
• Updated BTPayPalCheckoutRequest: Added a new optional property contactInformation of type BTContactInformation.
• The contactInformation.recipientEmail and contactInformation.recipientPhoneNumber are passed to the create_payment_resource endpoint as the recipient_email and international_phone parameters when present.

Note: When the new parameters (recipient_email and international_phone) are included, the gateway returns an error. I will follow up with updates once I gather more information or implement any necessary fixes.

Checklist

• Added a changelog entry
• Pending: Tested and confirmed payment flows affected by this change are functioning as expected

Authors

• @richherrera

[jaxdesmarais]

One small docstring comment but overall looks great!

[agedd]

lgtm! 🚀 just left one small comment