Removed redundant messaging authentication

[sdbondi]

Description

Comms-level (direct peer-to-peer) message authentication is a hangover
from the zMQ comms control port and can be removed.
Direct wire messages are authenticated by the noise protocol.
Comms-level messaging protocol simply sends blobs between peers similar to zMQ-style messaging

Motivation and Context

This reduces the number of bytes sent over the wire. Removes (de)serialization of envelopes and signature creation/verification on outbound/inbound messaging

Note this is a breaking network change. Getting all the breaking changes out of the way along with #1686

How Has This Been Tested?

Existing tests updated/removed (less code to test)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Feature refactor (No new feature or functional changes, but performance or technical debt improvements)
• New Tests
• Documentation

Checklist:

• I'm merging against the development branch.
• I ran cargo-fmt --all before pushing.
• I have squashed my commits into a single commit.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.

[CjS77]

LGTM

[neonknight64]

LGTM