Add pegasus-integrity-check callouts to pegasus-transfer

[von]

• Add extensions to pegasus-planner
• In current implementation are doing this outside of pegasus-transfer

[von]

@obisec & Steve have code, but haven't had a chance to review it. @rynge Would like feedback on if they are using the right crypto functions. Do test cases exist yet? No.

[von]

Plan to pick up in November