tokenIdentifier function returns principals that don't comply with the IC spec

[roman-kashitsyn]

IC Principals look like blobs, but they do have an internal structure described in https://smartcontracts.org/docs/interface-spec/index.html#principal.

The tokenIdentifier function contracts principals in a way that is not compatible with the public spec:

entrepot-app/src/ic/extjs.js

Lines 38 to 46 in e5e6d80

	const tokenIdentifier = (principal, index) => {
	const padding = Buffer("\x0Atid");
	const array = new Uint8Array([
	...padding,
	...Principal.fromText(principal).toUint8Array(),
	...to32bits(index),
	]);
	return Principal.fromUint8Array(array).toText();
	};

Possible solutions:

1. Use a raw Blob as an identifier (probably the simplest solution).
2. Construct "derived ids" as described in the spec (using a canister ID as a registering principal, for example).