Fix dynamic shell completions by correcting parameter names
Dynamic completions for the CLI were not working because completion
functions used `_prefix` as the first parameter name instead of `prefix`.
This is incompatible with how `argcomplete` passes it's arguments.
Add regression test for the prefix parameter as well as some basic shell
completion testing.
When a machine is deleted with `clan machines delete`, remove its
vars and legacy secrets, and update any secrets that reference the
machine's key.
This command is a superset of `clan secrets machine delete`, and I am
wondering if we could remove the `clan secrets machine` subcommand,
unless there is an use case for having a machine defined without its
key, and any secrets/vars?
Note:
- This deletes the `ListSecretsOptions` dataclass, as it did not seem to
bring any value, especially since `list_secrets` was receiving its
individual members instead of the whole dataclass. We can always bring
it back if complexity grows to demand it.
Add a dynamic completer for `tags`.
Queries tag information from:
- the keys of the computed/static tags (inventory tags)
- the services tags
- the machines tags
In recent nix versions the `nix flake show` command busts the eval
cache, which made the function that used to be faster, slower.
On benchmarks the completion was around 180-200ms.
Add dynamic completion scaffolding to the clan `cli`.
Also add a dynamic completion mechanism for machines for commands that
have machines as their sole argument.
More intricate dynamic completions will be implemented in follow up
PR's.
