Allow package filtering

[ivanayov]

A proposal by @puerco.

Currently the sbom-composer adds all packages from micro SBOMs to the final document.

We would like to support something like:

compose --exclude-package <package_name>

or via the config.yaml:

excludedPackages:
  - package1
  - package2
  ...

What other elements should be allowed for filtering?

• Packages are the bare minimum
• If a package is excluded from the composed doc, all elements it's related to should be excluded as well
• Others?