Add more tests, benchmarks and examples

[radumarias]

Add more Rust tests https://github.com/radumarias/zeroize-python/blob/main/src/lib.rs#L139

You can add also benchmarks.

You can take logic from
https://github.com/radumarias/zeroize-python/blob/main/tests/test_zeroize.py
https://github.com/radumarias/zeroize-python/tree/main/examples

You can also add more Python examples.

https://youtu.be/MiLp0InGOkI?si=xrt3V57DuL1uG2Vr