Add vulnerability severity data to command output.

[iamdharmesh]

Description of the Change

PR adds severity data of vulnerability in command output.

Closes #85

How to test the Change

1. Configure this scanner repo and configure API provider
2. Run commands like wp vuln status, wp vuln theme-status etc... and make sure severity details are there.

Changelog Entry

Added - Vulnerability severity data to command output.

Credits

Props @iamdharmesh

Checklist:

• [x] I agree to follow this project's Code of Conduct.
• [ ] I have updated the documentation accordingly.
• [ ] I have added tests to cover my change.
• [ ] All new and existing tests pass.

[jeffpaul]

@iamdharmesh is this ready to send out for review or still work in progress?

[iamdharmesh]

@iamdharmesh is this ready to send out for review or still work in progress?

@jeffpaul work is done, but Tests for Wordfence are failing. So, I have made a PR draft until I figure out the root cause for the failure and sort it out.

[iamdharmesh]

@jeffpaul this is ready for review now.