refactor(auth): make Buffer use more idiomatic

[eventualbuddha]

Overview

We don't need the numericArray helper or spreading into array literals passed to Buffer.from calls. Instead, we should use the more idiomatic and efficient Buffer.alloc and Buffer.concat calls. This also changes Buffer.from([…]) calls to Buffer.of(…) as the intermediate array is just extra noise (they probably amount to about the same in terms of perf for small N, at any rate).

Demo Video or Screenshot

n/a

Testing Plan

Automated

[arsalansufi]

Thanks for tweaking!