Include Plugins in SBOM generation

While generating the SBOM include all the plugins from the project as well. The plugins could also have issues or could be used for component tracking/tracing on where used in projects.

Per @stevespringett
> I think implementation of it would likely have to wait until https://github.com/CycloneDX/specification/issues/31 is implemented in the spec, but we can use Maven plugin case to drive some of the use cases.

_Originally posted by @stevespringett in https://github.com/CycloneDX/cyclonedx-maven-plugin/issues/165#issuecomment-1058419698_