Add a +benchmark mode to act-wrapper.

[ximon18]

Simplifies making a resource usage graph while loading and signing a specified zone using a specified policy.

Example usage, assuming policy file and zone file pre-exist:

$ ./act-wrapper +benchmark se ./se.zone.txt.stripped ./some-policy.toml 300

This will run integration-tests/benchmark-test.yml which will load the specified zone and sign it using the specified policy, and create a PNG image output file in the current directory called benchmark-<YYYYmmdd_HHMMSS>.png showing resource usage during that process.

This PR also reduces the produced image size as I decided I prefer the smaller size / larger ratio of text size to image size.

The 300 is an optional timeout in seconds which is needed because loading and signing a large zone takes longer than the default 10s timeout.

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• If you are changing Rust code or integration tests (Cargo.*, crates/, etc/, integration-tests/, src/):
  • Did you run the integration tests with act through the act-wrapper (as described in TESTING.md)?