Move utils to a new repo

[mrcnski]

Overview

A lot of the utilities in the utils folder are needed in other JS projects, e.g.:

• Conversion functions e.g. hexToUint8Array
• Crypto functions e.g. sha512
• The validation functions e.g. validateHexString
• etc.

In skynet-mysky we have been copy/pasting these utility functions from skynet-js, but that increases the maintenance burden if they ever need to be updated.

Design or Proposal

• Create a new repo e.g. skynet-utils
• Move all utilities from skynet-js not specific to skynet-js to the new repo.
• Publish the new repo
• Use skynet-utils as a dependency in skynet-js
• Use skynet-utils as a dependency in skynet-mysky