New global PR /pulls dashboard (M3) [GA]

### Value Prop

The new global Pull Requests experience on github.com/pulls provides a redesigned, high-performance hub for developers to view and manage all of their pull requests across GitHub in one place. With enhanced search and filtering and customizable saved views, developers can quickly find what matters most and stay on top of their code review workflows.

### Expected Outcome

With the new /pulls experience, developers can expect to spend less time searching for relevant pull requests and more time shipping code. Saved views enable developers to tailor the experience to their unique workflows and preferences, while improved performance and a modern UI reduce context-switching and accelerate review cycles.