[orchestrator]: reduce dead_code warnings

### Problem:
https://github.com/aws/s2n-netbench/pull/28#discussion_r1600756779

There is currently a bunch of `#[allow(dead_code)]` since we compile two [`bin`s](https://github.com/aws/s2n-netbench/blob/main/netbench-orchestrator/Cargo.toml#L11-L17) and this results in some code not being used.

Start with netbench-orchestrator/Cargo.toml and the two bin targets linked in the issue, then read the referenced pull-request discussion. Inventory the #[allow(dead_code)] cases and determine which code each binary uses. Done means the orchestrator builds both binaries without unnecessary dead_code warnings.

Written by the indexing model from the issue text.