feat(github): improve pr enriched data

[setchy]

Summary
Refines how pull request review information is aggregated and displayed in notification metrics, including reviewer state grouping and review-thread resolution counts.

Changes

• Aggregate reviewers by their latest review state instead of listing all reviews.
• Include reviewer names in review metric tooltips.
• Decouple getPullRequestReviewIcon from GitifyPullRequestReview; it now accepts a local PullRequestReviewGroup type.
• Extend the GitHub GraphQL pull request query with reviewer and review-thread data needed for aggregation.
• Update ReviewsPill to compute grouped review states and thread totals from the new reviewer model.
• Add/adjust tests across the pull request handler, GraphQL client, icon utilities, and ReviewsPill component to cover the new aggregation and grouping logic.

Testing

• Pull request handler tests (reviewer aggregation, ordering by submittedAt, review-thread merging).
• GraphQL client and query tests.
• Icon utility tests updated for the new PullRequestReviewGroup type.
• ReviewsPill component tests and snapshots.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
89.7% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud