Tracking issue for configs that could cross version boundaries

https://github.com/oxidecomputer/omicron/issues/3703 and https://github.com/oxidecomputer/omicron/issues/3407 are related to this.

It would be nice to have an EXPECTORATE tool for validating the formats of the following configs, and ensure we don't unintentionally introduce breakages while upgrading the sled agent or related components.

• https://github.com/oxidecomputer/omicron/pull/3715
  • Service ledger - services.toml (stored in the config dataset to allow the sled agent to re-instantiate services)
  • Zone bundle Metadata - metadata.toml (stored in the config dataset to track debug bundles)
  • Nexus's configuration file, which is processed and created by the sled agent - (constructed dynamically while creating the Nexus zone)
  • The bootstrap's notion of "how to launch the sled agent" - sled-agent-request.toml
  • The Rack Setup Service's sled and service plans: rss-sled-plan.toml, rss-service-plan.toml
• Bootstore config: bootstore-fsm-state.json
• Bootstore config: bootstore-network-config.json

Start by reading bootstore-fsm-state.json and bootstore-network-config.json, then review related issues 3703 and 3407 for the compatibility requirements. Done means both remaining bootstore formats are validated across version boundaries and unintended upgrade breakages are covered by the resulting checks.