Connect PE Universal API to Crossfeed

# 💡 Summary #

This was an unplanned task for Sprint 1, that allows for the Crossfeed application connect with the P&E database via API.

## Motivation and context ##

In its completion this ticket will unblock [Redesign Vuln Details Page: Overview Section](https://github.com/cisagov/crossfeed/issues/2306), [Redesign Vuln Details Page: CVC Highlight](https://github.com/cisagov/crossfeed/issues/2307), [Redesign Vuln Details Page: CVE References & CWE](https://github.com/cisagov/crossfeed/issues/2308), [Redesign Vuln Details Page: Severity, Affected, History & Notes](https://github.com/cisagov/crossfeed/issues/2309). Data found in the P&E database would be used to populate the Vulnerability Details page.

## Acceptance criteria ##

How do we know when this work is done?

- [ ] Access to PE database is available via API