Add ability to supply custom package supplier value

[ByAgenT]

This PR adds new argument to provide supplier (organization) for generated SBOM.

Remaining to-do:

• [x] Add assembly attribute for supply parameter.
• [x] Add associated tests.
• [x] Update documentation to CLI include -ps parameter usage.
• [x] Update documentation to the API to include PackageSupplier in SBOMMetadata.

Resolves #84