Update CLI for update status + TUF repo list + related changes

[david-crespo]

This integrates the API spec from oxidecomputer/omicron#9106 (TUF repo list), which is built on oxidecomputer/omicron#8897 (update status), so it includes both.

Posting this already because I want to minimize the amount of time after oxidecomputer/omicron#9106 is merged in which the CLI is unusable for update dev work.

This moves the commands for CRUD on trust roots out of experimental, as well as moving repo list, repo view, and set target release (upload was already at oxide system update repo upload). That gives us:

system update repo list
system update repo upload
system update repo view
system update status
system update target-release update
system update trust-root create
system update trust-root delete
system update trust-root list
system update trust-root view

Viewing the current target release is rolled into status.

[ahl]

Bravo