`reveal_type` should show sub expressions

```
👉 Mypy -c "reveal_type(bar(foo(1)))"
Input.py:1: note: Revealed type is:
bar(foo(1))
^ ^
| (int) -> str
(str) -> Bar[str]

Result: Bar[str]
Success
```

This would be useful for figuring out what generics and overloads have been resolved to.

Start by reproducing the example with `mypy -c "reveal_type(bar(foo(1)))"` and inspect how `reveal_type` reports the expression. Done means the output shows the resolved types of the nested calls and the overall result, while the command still finishes successfully.

Written by the indexing model from the issue text.