Add performance tests

[twoeths]

This statistic shows that the hash of go is ~6x faster than as

#	minTime(ms)	maxTime(ms)	average(ms)
go	11	108	14
as	61	480	82

This link https://gist.github.com/scoroberts/a60d61a2cc3afba1e8813b338ecd1501 shows that the current as implementation is comparable to java's (added a test for that).

[CLAassistant]

All committers have signed the CLA.

[dapplion]

Could we investigate the hashing power of Prysm's and Lighthouse's respective sha256 libs?

[twoeths]

Could we investigate the hashing power of Prysm's and Lighthouse's respective sha256 libs?

#	minTime(ms)	maxTime(ms)	average(ms)
go	11	108	14
rust	55	262	63
as	61	480	82

[dapplion]

Could we investigate the hashing power of Prysm's and Lighthouse's respective sha256 libs?

go 11 108 14
rust 55 262 63
as 61 480 82

That's to perform 1 hash or how many?

[MaxGraey]

• [Go] sha256 in Prysm uses simd optimized native SHA256

• [Rust] sha256 in Lighthouse use sha2 crate which also native

• [AssemblyScript] version of Sha256 use WebAasembly which slower than native and has interop overhead and without SIMD

I just want to draw your attention to this. Since, in essence, you are comparing 3 completely different platforms in different conditions

[twoeths]

Could we investigate the hashing power of Prysm's and Lighthouse's respective sha256 libs?

go 11 108 14
rust 55 262 63
as 61 480 82

That's to perform 1 hash or how many?

it's to hash byte array from this string "lwkjt23uy45pojsdf;lnwo45y23po5i;lknwe;lknasdflnqw3uo5" 50000 times, similar to our performance test