Overhaul packaging, launching services within a omicron1 branded zones

[smklein]

This PR provides support for launching and managing services as zones.

What's happening here

Nexus

• Exposes types in a way which can interoperate with Sled Agent.

Sled Agent

• Parse a config file, rather than taking arguments over CLI
• Add a "Service Manager", responsible for zones that run independently of datasets (e.g., Nexus, Oximeter)

Networking

• Allow specifying static IP addresses for Zone addresses
• In doing so: Add some utilities to sled-agent/src/illumos/zone.rs to ensure that link-local addresses are available for IPv6 addressing. This lets us provide static IPv6 addresses for services, which we use elsewhere in the PR when setting up zones.

Storage

• Adds a "filesystem_put" endpoint to the Sled Agent, which allows a caller to request the creation of a local filesystem.
• Adds a "service_put" endpoint to the Sled Agent, which allows a caller to request the creation of a local service.
• Enable installation of omicron1 branded zones.
• Overhaul the process of auto-loading installed zones and managing running zones.

Bootstrapping

• Enable the parsing of a config-rss.toml file, which provides requests that would normally arrive from the Rack Setup Service.
• Process the "rss requests" in the bootstrap agent, where they are injected before starting any local services.

Packaging Tools

• Rely on omicron-package for package construction.
• Adds a new "zone" type package to omicron-package, allowing the creation of omicron1-branded *.tar.gz files.
• Adds a "cockroachdb", "clickhouse" packages to package-manifest.toml, with an associated manifest.xml file.

[jmpesp]

🎉 🚀