Use stream consumers

[jimmywarting]

NodeJS released some stream consumers utility, so brought it to the userland

thought we could use it in both the node-fetch body mixin and also in the fetch-blob package.
Grate thing about it is that it operates on async iterator, so it can work with both async iterators, whatwg & node streams

( node-fetch/node-fetch#1252 )

[jimmywarting]

on 2nd thought it would have a circular dependency cuz my userland version depends upon this package... so maybe wouldn't be so such a good idea...