Fix ZKAPAuthorizerStorageServer implementer declaration to avoid need to register adapter

Handle unrecognized redemption failure reasons

Run black and isort over the codebase.

This removes the need to call `registerAdapter` on
`ZKAPAuthorizerStorageServer`. It looks like that was needed because the
interfaces for it were defined by `implementer_only` which explicitly ignored
interfaces defined by parent classes. Looking at the history, I assume the use
of `implementer_only` was to avoid implementing `RIStorageServer` via
`proxyForInterface`. Given that the later is no longer used, `implementer_only`
is no longer necessary.

Close the trust loop

Update mach-nix to fix accidentally quadratic behavior.

Update mach-nix to an upstream version.

Switch to using mach-nix for python packaging.