Add recursive wildcard for ignore_imports

[ngnpope]

Support for wildcards was added in #106, but it would be nice if this could be enhanced to support a recursive wildcard.

This would allow simplifying something like this:

ignore_imports = [
    "foo.* -> bar.something",
    "foo.* -> baz.something",
    "foo.*.* -> bar.something",
    "foo.*.* -> baz.something",
    "foo.*.*.* -> bar.something",
    "foo.*.*.* -> baz.something",
    "bar.something -> baz.*.*.*.other",
]

Such that we could have the following:

ignore_imports = [
    "foo.** -> bar.something",
    "foo.** -> baz.something",
    "bar.something -> baz.**.other",
]

This would be useful when adding import-linter to existing large projects where the ignore list can be large.

[seddonym]

I agree, that would be nice. Happy to consider a pull request if anyone wants to submit one.