Add microbenchmarks about ztunnel

[thesurlydev]

I can take this one and at least get the bare minimum scaffold setup.

My intent is to create a benches directory to the project root and add a few benches. As a follow-up it makes sense to add a job to Prow for this to run on a cron schedule.

[stevenctl]

Connection init with HBONE

Throughput?

Config ingestion?

Identify components that need this. It’s most likely these will be added as-needed to tackle specific issues.

[howardjohn]

This is pretty simialr to #99. Id scope this task to microbenchmarks that are not exercising a real network call, etc.

There may not actually be many functions that qualify in that category though

[howardjohn]

These were added for the main traffic flow and metrics