R1:8810cd2f4d15

Add a standalone view for the Maniphest task graph

Summary:
See PHI1073. Improve the UX here:

- When there are a small number of connected tasks, no changes.
- When there are too many total connected tasks, but not too many directly connected tasks, show hint text with a "View Standalone Graph" button to view more of the graph.
- When there are too many directly connected tasks, show better hint text with a "View Standalone Graph" button.
- Always show a "View Standalone Graph" option in the…