[ty] Determine value vs. type syntax highlighting based on call arguments (#23949)
## Summary
We now expose a method to determine whether a call argument should be
treated as a type form (or not), for the purposes of syntax
highlighting.
This is more difficult than it may sound, largely due to the existence
of overloads and conditional bindings. For example, given the following:
```python
from typing import cast
from typing_extensions import assert_type
func = cast if flag else assert_type
```
The highlighting we want to use for various arguments has to taken into
account both the signatures of `cast` and `assert_type`, along with the
type of the value provided to the argument.
For example, given:
```python
f(val=x, typ=int)
```
Both agree that `val=x` is a value, and `typ=int` is a type form.
But given:
```python
f(x, int)
```
Both match, but disagree:
- `cast(x, int)` treats the arguments as `[Type, Value]`
- `assert_type(x, int)` treats them as `[Value, Type]`
So we treat them both as unknown.
Closes https://github.com/astral-sh/ty/issues/3038.
ruff
0f5f93b8 - [ty] Determine value vs. type syntax highlighting based on call arguments (#23949)
