Add sinus and cosinus for SD59x18

[Amxx]

(work in progress)

[Amxx]

Note: https://github.com/mds1/solidity-trigonometry/blob/main/src/Trigonometry.sol should be considered. I don't understand the underlying logic, but if translated to signed integers, it might be cheaper / more accurate ?

[PaulRBerg]

Hi @Amxx, thank you for your PR. I just wanted to say that it might take a few weeks (or more) until I'm able to review this.

The lint job appears to be failing. Have you run forge fmt locally? Using VSCode should automatically do this for you.

[Amxx]

@PaulRBerg Sure, not rush. There may be otehr implementations that deserves exploring anyway.