tidy-imports --black with custom line length (PyInf#11045)

[sac111gp]

This is a request for below 2 items:

Bug fix:

1. Make tidy-imports --black respect black's configured line length (e.g., via pyproject.toml)

Enhancement:

1. Make tidy-imports --black --width respect line length. Currently, it is a known and documented behavior in --help of --black option:

    --black             Use black to format imports. If this option is used,
                        all other formatting options are ignored.

We'd like to allow configuring line length via --width as well when used with black.