Introduce project-groups

[ben-edna]

With larger set of projects it would be nice to be able to group them together. For instance, dependencies that are used for production code, or documentation relating projects.

Proposal would be to follow the same syntax and structure as zephyr west does:

https://docs.zephyrproject.org/latest/guides/west/manifest.html#project-groups

[spoorcc]

This would make SBoM's possible that "ignore" development artifacts.

 Given the manifest 'dfetch.yaml'
    """
    manifest:
      version: '0.0'

      remotes:
        - name: my-repo
          url-base: https://github.com/org/repo

      projects:
        - name: dev-tools
          src: dev-tools
          groups:
              - development

        - name: PRODUCTION-LIB
          src: prod-lib
          groups:
              - production

    """
When I run "dfetch report -t 'sbom' development -o my-sbom.json"
Then only the 'dev-tools' project is part of the 'my-sbom.json'