LSP: Provide key autocompletion on annotated `TypedDict`

### Describe the Bug

I'd like to have key autocompletion suggestions when constructing an annotated `TypedDict`.

Example:

```python
from typing import TypedDict

class Dimension(TypedDict):
x: int
y: int
z: int

def main():
dimensions: Dimension = {"x": 5}

if __name__ == "__main__":
main()
```

### Sandbox Link

https://pyrefly.org/sandbox/?project=N4IgZglgNgpgziAXKOBDAdgEwEYHsAeAdAA4CeS4ATrgLYAEALqcROgOZ0Q3G6UN0AVZjEwARCAGMGAHXSzZEqKjhw64mjHRwIudAAohxEeKkBKRLLpW6%2BRJ3Qz01uqTutHzgF5uH8uVhgwOhpUVj1zS2tMLk1tXTg7dVidJwBeOmBpEHwsuwBWAF8-WQgggH0y9FQNCrpU9KyKkNYK3MirZv1TWRAAGhAAVwZoOBJyRBAAYjoAVWGoCCY6MAH0KRS4P0xA5d4QhkqBmmwYSj1bewZTOgBaAD46OAZKCydrShgGAconMCyAOSOJxeGXwRRAPX6ZA%2BYCgpEIDFoUAo0wACqQYXDHhgcAQ6BJdJA2N9UMNdIRZNMAMowGB0AAWDAYxASAHpWdDAnDCLw2KzNKzMLgJHBWQT0ESSWT0KzdpQ6KgAG6hJTYWD4wkQYmUUkpOi4YjS0ayMgMem6G6K05xNJ0LIAZkIAEYAExZHoFfqodZWgBi0BgFDQWDwRDIIAKQA

### (Only applicable for extension issues) IDE Information

_No response_