Evosax - CMA-ES

[RobertTLange]

• Reference: Hansen & Ostermeier (2001)
• evosax Source Code: https://github.com/RobertTLange/evosax/blob/main/evosax/strategies/cma_es.py
• This PR adds a JAX-based CMA-ES version, which runs on different hardware backends (CPU, GPU, TPU). It overlaps with #6, but does not run into OOM issues, etc. I hope no one is mad at me for pushing this, since there was no update on the other PR for a month.
• Benchmarks and hyperparameters:

	Benchmarks	Parameters	Results (Avg)
CartPole (easy)	900 (max_iter=1000)	Link	927.3208
CartPole (hard)	600 (max_iter=1000)	Link	625.9829
MNIST	90.0 (max_iter=2000)	Link	0.9581
Brax Ant	3000 (max_iter=1200)	Link	3174.0608
Waterworld	6 (max_iter=500)	Link	9.44
Waterworld (MA)	2 (max_iter=2000)	Link	0.5625

[lerrytang]

Thank you!