This set of changes refactors the canonical handling by isolating the business
logic into another type, `Canonical`.
The functionality remains the same, but certain error scenarios are better
handled. Primarily, the commits of the inner `Canonical` type are checked to see
if they exist in the working copy, and if not, provide a more useful message
about which commit was missing or invalid for which DID.
Pay more attention to when a Node ID is displayed in compact form. As
this was sometimes used to save space, e.g. in `rad node status` in
combination with long node addresses (like .onion names), also implement
a compact format for node addresses and use that instead in some cases.
Progress notifications in spinners keep the short form.
Add a test to exercise adding canonical reference rules and pushing new
canonical tags.
A change in `rad id` was required to allow adding a new payload to the document,
i.e. one that does not already exist.
Adding rules is also documented in the man page for `rad id`.
The business logic of modifying the identity document should not live in the CLI
code for updating said document.
Instead, we extract out that logic into separate update functions and these are
using from the CLI instead.
Fintan Halpenny
Lorenz Leutgeb