[iOS] Add Privacy Manifest to SEPADirectDebit module

[agedd]

Summary of changes

• Adds PrivacyInfo.xcprivacy to BraintreeSEPADirectDebit
• Adds corresponding Package.swift and Braintree.podspec changes

Checklist

• ~Added a changelog entry~

Authors

List GitHub usernames for everyone who contributed to this pull request.

• @agedd