Increase the speed of cataloger stage

[Mikcl]

What would you like to be added:

When running syft each cataloger is resolver serially.

To increase the speed of generating an sbom, catalogers can be resolved in parallel.

Why is this needed:

To save time.

Additional context:

This could be configurable/exposed via a new flag/field in the config file passed to syft (open to suggestion on the name) such as syft --workers N which would mean that N cataloger jobs are done in parallel instead of serially.