Regression

[dop-amin]

Adds a simple framework for running regression tetsts on SLOTHY's performance to CI.
Partially addresses #215.
Depends on #211.

[dop-amin]

For some reason ntt_dilithium_123_45678_a55 keeps failing due to immediate out of range issues. This was not the case with the previous optimization run in CI. Needs investigation.

[mkannwischer]

Here is the first test result:

keccak_f1600_x1_scalar_slothy_no_symbolic_a55: 2325.6789305686953
ntt_kyber_123_4567_a55: 249.27907199859618
keccakf1600_xkcp_m7: 1728.8838932037354
ntt_dilithium_m7: 16.455983209609986
ntt_kyber_m7: 2825.1233290195464
ntt_kyber_1_23_45_67_m55: 27.949791622161865
ntt_dilithium_12_34_56_78_m55: 28.257723569869995

I'll run it again to see how stable it is.

[dop-amin]

Could also be worth returning the variance