Add authenticated route to get consent preferences

[sanders41]

Purpose

Adds an authenticated route to get a user's consent preferences.

Changes

• Added an get_consent_preferences route.

Checklist

• Update CHANGELOG.md file
  • Merge in main so the most recent CHANGELOG.md file is being appended to
  • Add description within the Unreleased section in an appropriate category. Add a new category from the list at the top of the file if the needed one isn't already there.
  • Add a link to this PR at the end of the description with the PR number as the text. example: #1
• Applicable documentation updated (guides, quickstart, postman collections, tutorial, fidesdemo, database diagram.
• If docs updated (select one):
  • 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)
• Good unit test/integration test coverage
• This PR contains a DB migration. If checked, the reviewer should confirm with the author that the down_revision correctly references the previous migration before merging
• The Run Unsafe PR Checks label has been applied, and checks have passed, if this PR touches any external services

Ticket

Fixes #1225

[pattisdr]

Just a few requested changes along the same lines as the previous PR, I think this should be quick.

[pattisdr]

Great @sanders41

I'd add a followup ticket that adds these endpoints to the guides but this work by itself is ready to go