Add Multiple Disk Support for Image Build

[josephknierman]

This PR adds support for creating multiple disks for a specific image config. The PR adds some optional configs for adding IDs to Disks and allows setting an optional primary disk in the SystemConfiguration, which is used for determining where to install the bootloader. The PR assumes that all disks should be using the same target type. This PR is intended to have all single disk configurations work without any additional changes.

Merge Checklist

All boxes should be checked before merging the PR (just tick any boxes which don't apply to this PR)

• [ ] The toolchain has been rebuilt successfully (or no changes were made to it)
• [ ] The toolchain/worker package manifests are up-to-date
• [ ] Any updated packages successfully build (or no packages were changed)
• [ ] Packages depending on static components modified in this PR (Golang, *-static subpackages, etc.) have had their Release tag incremented.
• [ ] Package tests (%check section) have been verified with RUN_CHECK=y for existing SPEC files, or added to new SPEC files
• [ ] All package sources are available
• [ ] cgmanifest files are up-to-date and sorted (./cgmanifest.json, ./toolkit/tools/cgmanifest.json, ./toolkit/scripts/toolchain/cgmanifest.json, .github/workflows/cgmanifest.json)
• [ ] LICENSE-MAP files are up-to-date (./SPECS/LICENSES-AND-NOTICES/data/licenses.json, ./SPECS/LICENSES-AND-NOTICES/LICENSES-MAP.md, ./SPECS/LICENSES-AND-NOTICES/LICENSE-EXCEPTIONS.PHOTON)
• [ ] All source files have up-to-date hashes in the *.signatures.json files
• [ ] sudo make go-tidy-all and sudo make go-test-coverage pass
• [ ] Documentation has been updated to match any changes to the build system
• [ ] Ready to merge

---

Summary

What does the PR accomplish, why was it needed?

Change Log

• Change
• Change
• Change

Does this affect the toolchain?

YES/NO

Associated issues

• #xxxx

Links to CVEs

• https://nvd.nist.gov/vuln/detail/CVE-YYYY-XXXX

Test Methodology

• Pipeline build id: xxxx