Add encoding helpers for frontend serialization to common library

[aaroncox]

From discussions in telegram starting here:

https://t.me/wharfkit/2112

We should add some common helpers to allow easy serialization to a common format for use in JS contexts where the native Antelope types aren't well supported (like persisting data to local storage or something).

The helpers we have in Anchor Desktop 2.0 might be good for this?

https://github.com/wharfkit/example-vite-svelte-ts/blob/master/src/lib/Login.svelte#L59