R1:0aee3da19e6a

Add a "Reports" menu item to Projects

Summary:
Ref T13279. Since the use cases that have made it upstream are all for relatively complex charts (e.g., requiring aggregation and composition of multiple data series in nontrivial ways) I'm currently looking at an overall approach like this:

- At least for now, Charts provides a low-level internal-only API for composing charts from raw datasets.
- This is exposed to users through pre-built `SearchEngine`-like interfaces that provide a small number of…