feat(recommendations): Recommendations infra P1

[jjoyce0510]

Summary
This PR introduces extensible infrastructure required for displaying catalog recommendations in the UI! It includes the surface area for presenting server-driven recommendations on the home page, search page, and entity pages.

Changes

The fun parts:

Server

• RecommendationService for sourcing candidates for recommendations to present to the UI in a given UI
• RecommendationCandidateSource, an interface to implement for generating recommendations. Implementations include RecentlyViewed, HighlyUsed, TopPlatforms, TopTags, TopTerms
• RecommendationModuleRanker for ranking the recommended results

UI

• RecommendationRendererRegistry for registering the handlers invoked to render recommendations for each render type

Screenshots
Home Page:

Search Page:

Status
Ready for review.

Checklist

• The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• Links to related issues (if applicable)
• Tests for the changes have been added/updated (if applicable)
• Docs related to the changes have been added/updated (if applicable)

[github-actions]

Unit Test Results

     58 files  +2       58 suites  +2   20m 15s ⏱️ - 3m 37s
   525 tests +7     473 ✔️ +7  52 💤 ±0  0 ❌ ±0 
1 174 runs  +7  1 100 ✔️ +1  74 💤 +6  0 ❌ ±0 

Results for commit ee2e0ab. ± Comparison against base commit 87e93ab.

♻️ This comment has been updated with latest results.

[shirshanka]

LGTM - Really excited to see Recommendations in action!