Investigate changes in SERVER-41490: Disable OP_MSG checksums for TLS connections

Description

SERVER ticket description:

We enabled OP_MSG checksums to catch data corruption on the wire in SERVER-28679.

This work of performing those checksums is extra cost though, and it is redundant when mixed with the hmacs required by tls.

We lose little on the data integrity side and avoid overhead if we only perform check sums on non-tls connections.

Change Description:

We should document that we'll never checksum op_msg packets if tls is on

Scope of changes

Impact to Other Docs

MVP (Work and Date)

Resources (Scope or Design Docs, Invision, etc.)