fix: a couple p2p transfer fixes to match spec

[tessstoddard]

Summary of Changes

Small fixes that need to be made for p2p transfers

• Fix a few paths for frequencies and cancel p2p transfer/recurring transfer
• Refactor delete methods -> cancel methods for p2p transfer/recurring transfer

Downstream Consumer Impact

None. These endpoints are still in development and only for GCU

How Has This Been Tested?

Unit tests have been updated. Verified matches spec

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works