Confusing error using intersection operator (`&`) in value position (eg `TypeVar` bounds)

```python
from typing import TypeVar

class Foo: ...
class Bar: ...

T = TypeVar("T", bound=Foo & Bar)
# error: TypeVar "bound" must be a type
# error: Unsupported left operand type for & ("type[Foo]")
```

Something more like "Use quoted types or basedtyping.Intersection".

Start by reproducing the TypeVar example using an intersection expression in the bound value position. Trace where the reported errors are generated and update the diagnostic so it suggests quoted types or basedtyping.Intersection; done when this example produces the clearer guidance.

Written by the indexing model from the issue text.