privacy-center: Introduce fides-consent script package

[ssangervasi]

Closes #1395

Code Changes

• Adds fides-consent.js, exposing the our cookie parsing logic in a browser script.
• E2E tests the consent set->get flow using a standalone page.
• The privacy center uses the same code from the module for its cookie logic.

Steps to Confirm

• Build and test the script
  • npm install and npm run cy:start should put everything in place automatically
• Try it in dev
  • The demo page should reflect the changes made in the privacy center.
  • http://localhost:3000/fides-consent-demo.html

Pre-Merge Checklist

• All CI Pipelines Succeeded
• Documentation Updated:
  • documentation complete, or draft/outline provided (tag docs-team to complete/review on this branch)
  • documentation issue created (tag docs-team to complete issue separately)
• Issue Requirements are Met
• Relevant Follow-Up Issues Created
• Update CHANGELOG.md

Description Of Changes

Actually writing the script was easy, but figuring out a good build + test flow was quite interesting. I used rollup, just like we have in fidesui. Next.js wouldn't let me use <script> tag with a static asset, so for testing I created a static HTML page that is simply served as-is. This is probably better for isolation anyway.

[LKCSmith]

I think the code looks good, but I get a 404 page doesn't exist when trying to access http://localhost:3000/fides-consent-demo.html -- does a flag need to be active?

[ssangervasi]

I think the code looks good, but I get a 404 page doesn't exist when trying to access http://localhost:3000/fides-consent-demo.html -- does a flag need to be active?

@LKCSmith - Running npm run dev from the privacy-center directory works for me. And npm run cy:start hosts a built version.