Provide a `--report` flag that gives a complete report of build times

I suggest adding a `--report` flag to `cabal build` that outputs a complete report of where time is being spent, including:

- Running the solver.
- Per package breakdown:
- Time spent configuring.
- Time spent building, possibly also including some information from `ghc -dshow-passes`.
- Time spent in registering/installing.

Having a single command that immediately gives an overview would be useful to quickly diagnose why builds are slow.

Start with the cabal build command and map how it records the solver, per-package configuration, building, and registering/installing phases. Compare the available build timing information with the optional ghc -dshow-passes data; done means --report presents a complete, useful breakdown covering each requested area.

Written by the indexing model from the issue text.