Implement encryption for Federate<>RTI control messages

[timpokorny]

Summary

To support encrypted communications (#240), all control messages exchanged between a federate and the RTI must be encrypted. We use PKI for this, where:

• The RTI will use public key of target federate to encrypt all control messages sent to it
• Federates will use public key of RTI to encrypt all control messages to the RTI

This ticket will ensure that all control messages exchanged between federates and the RTI will be encrypted as above.

Acceptance Criteria

Once complete, Portico shall:

• [x] encrypt all control communications from a federate >> RTI witih the public key of the RTI
• [x] encrypt all control communications from RTI >> federate with the public key of the federate
• [x] verify the above via wireshark

[timpokorny]

This is now done and on the central RTI branch.

It is a little different and depends on whether Public key or shared key crypto is being used.