dataview based readwrite num bytes opts

[g11tech]

This PR replaces the byte extract from uint number via native dataview, which is roughly 2x faster extraction than normal loop.
when plugged in it gives whopping 80% performace improvement over normal uint byte extraction and a marginal 3-5% improvement in the new uint64 tree backed datatype manipulation.

before:

after:

partially closes #143

[CLAassistant]

All committers have signed the CLA.

[dapplion]

Yeah DataView ops are so much faster than manual manipulation with currently do. All this optimizations are found in a similar form in #223 should we close this one in favor of #223 ?

[wemeetagain]

@dapplion 👍