Create a CID from a string or Uint8Array or CID-like object

This module has a number of ways of converting things into CID instances - CID.parse for strings, CID.decode for Uint8Arrays, CID.asCID for things CID-shaped.

.parse and .decode will throw, .asCID will not. We generally want to validate what we've been passed as a CID, so a common pattern seems to be forming as:

function toCID (hash) {
  if (typeof hash === 'string') {
    return CID.parse(hash)
  } else if (hash instanceof Uint8Array) {
    return CID.decode(hash)
  }

  const cid = CID.asCID(hash)
  
  if (!cid) {
    throw new Error('Invalid CID')
  }

  return cid
}

If this seems familiar it may be because this is quite similar to how the constructor from the js-cids class behaves.

It is quite useful though, any objections to making this a utility method on the CID class?

Start by locating the CID class and its existing parse, decode, and asCID methods. Check how CID construction and validation are tested, then confirm that the proposed utility accepts strings, Uint8Arrays, and CID-like objects while rejecting invalid values consistently.