BR-2180: Add pullquote module variant

Add variant hubs to pullquote module. Needed for Billboard Hubs which has a specific design that is different from pullquote module used in articles or other post types.
Made styles generic so other brand hubs can use in future. Specific styles to be added at theme level.
Ticket ref: https://penskemedia.atlassian.net/browse/BR-2180

[x] Updated root CHANGELOG.md with summary of changes under Unpublished section
[x] npm run prod in this repo outputs expected changes (excepting the issue with re-ordered partials in larva-css algorithms partials - see LRVA-1885)
[ ] If adding a new pattern, in the PR comment, included a screenshot and link to the static Vercel deployment
[ ] If changes to build scripts or the Node.js server, tested changes in pmc-spark via a pre-release
- If changes to build tools: npm scripts prod, lint, and dev scripts run as expected
- If changes to Larva server: Static site generates as expected in a theme (avail. on a URL {brand}.stg.larva.pmcdev.io)

penske-media-corp / pmc-larva