Add more tests and benchmarks

[radumarias]

Add more tests for other ciphers too in https://github.com/radumarias/rencrypt-python/blob/main/src/lib.rs#L242

You can take flow from https://github.com/radumarias/rencrypt-python/tree/main/examples and add tests for those in Rust.

You can also add tests in dedicated ciphers module files.

You can add benchmarks for each cipher also.

Also more Python tests would be helpful https://github.com/radumarias/rencrypt-python/blob/main/tests/test_rencrypt.py

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