Avoid args on a single separated line when formatting top-level function definitions

[iamdefinitelyahuman]

When formatting a top-level function definition that exceeds the max line length, the normal black behavior of "look at the contents of the first outer matching brackets and put that in a separate indented line" results in a function selector that can be hard to read:

@external
def celery_man(
    enable_43d3d3: bool, oyster_smiling_printout: bool, flarhgunnstow: bool
) -> (uint256, bool):
    ...

In this case I think it is better to skip to the behavior of placing each argument on a separate line:

@external
def celery_man(
    enable_43d3d3: bool,
    oyster_smiling_printout: bool,
    flarhgunnstow: bool,
) -> (uint256, bool):
    ...