Add benchmark scripts

[ZCG-coder]

A new script, benchmark.py has been added into the tools directory. It can run the Steppable executables
while timing them, and outputs a graph about its performance compared to the system method.

Changelog

• Added benchmarks.
• Fix requirements problem by moving to poetry.
• Update to cache@v4.
• Using pyproject.toml
• Fix benchmark.
• Made benchmark more verbose.
• Add more benchmark images.
• Improve figure format