chore(antithesis): dogstatsd generation with byte limit

This commit updates the harness driver to build dogstatsd to a byte
limit, in the manner of datadog/lading. I have been unable to
investigate SMPTNG-7611 well owing to the error log emission by Datadog
Agent. I've added property tests to assert the payload limit is obeyed,
accepting that this means making the dogstatsd generator pure with
regard to Rng and may not use antithesis SDK's random_* directly.

Author: blt