Add package description/summary to json output

**What would you like to be added**:

Add rpm/gem/npm package description to json output

**Why is this needed**:
It's a required field for our company's internal SBOM. It might be required by other companies as well.

**Additional context**:

It would be similar to dnf/yum repoquery -queryformat "%{summary}"

No file or test is named. Start by tracing Syft's JSON output path and where RPM, gem, and npm package metadata is represented; done when each package's description or summary appears in JSON and existing output tests pass.

Written by the indexing model from the issue text.