Deprecate printing commands invoked from the command library in the reports

[nishakm]

Problem Statement
The reports are becoming too verbose when printing out in detail the commands that were used to fetch the metadata information. The logging already has this information.

Describe the Proposal
Simplify the information printed in the final reports.

Steps to Implement Proposal

1. Move the individual package information to the Package Origins rather than ImageLayer Origins.
2. For ImageLayer Origins, just print that the metadata was retrieved using Tern's default method of operation.

Related issue: #752

[nishakm]

@rnjudge what do you think about turning:

Docker image: photon:3.0:
        Layer 1:
                info: Found 'VMware Photon OS/Linux' in /etc/os-release.
                info: Retrieved by invoking listing in command_lib/base.yml
versions:
        in container:
        tdnf check-update > /dev/null
        list=`tdnf list installed`
        c=0; for l in $list; do if [ $c == 1 ]; then echo $l; fi; c=$(((c+1)%3)); done;

names:
        in container:
        tdnf check-update > /dev/null
        tdnf list installed | cut -f1 -d"."


proj_urls:
        in container:
        tdnf check-update > /dev/null
        pkgs=`tdnf list installed | cut -f1 -d"."`
        for p in $pkgs; do tdnf info $p | head -9 | tail -1 | cut -f2-3 -d":" | xargs; done

licenses:
        in container:
        tdnf check-update > /dev/null
        pkgs=`tdnf list installed | cut -f1 -d"."`
        for p in $pkgs; do tdnf info $p | head -10 | tail -1 | cut -f2 -d":" | xargs; done



                warning: No listing method for 'srcs'. Additional analysis may be required.
No listing method for 'copyrights'. Additional analysis may be required.

into

Docker image: photon:3.0:
        Layer 1:
                OS: VMware Photon OS/Linux
                Package Format: rpm

The actual notices will not go away and will still exist in the json, yaml and html formats.