get parent flags in command

### Feature request

For there to be a way to check a parent flag from a command, or to process parent flags before the command.

### Why?

To support the following usage:
```sh
git --no-pager log --pretty=oneline
```

I would like to know that `--no-pager` was passed in from `log`.

### Alternatives

_No response_

### Additional context

_No response_