Add utility to select things with compatible tags

[sbidoul]

Coming from #1092 (comment), this PR proposes a utility to select things that best match an ordered list of tags.

It works like this, for instance, to select compatible wheel filenames:

    >>> filenames = ["foo-1.0-py3-none-any.whl", "foo-1.0-py2-none-any.whl"]
    >>> selector = create_compatible_tags_selector(tags.sys_tags())
    >>> compatible_filenames = list(selector([
    ...     (filename, parse_wheel_filename(filename)[-1]) for filename in filenames
    ... ]))
    ["foo-1.0-py3-none-any.whl"]

[sbidoul]

@brettcannon how do you like this one?

[sbidoul]

I made it return an iterator to allow for possible future optimizations.

So obtaining the best compatible wheel looks like this:

    >>> filenames = ["foo-1.0-py3-none-any.whl", "foo-1.0-py2-none-any.whl"]
    >>> selector = create_compatible_tags_selector(tags.sys_tags())
    >>> next(selector([
    ...     (filename, parse_wheel_filename(filename)[-1]) for filename in filenames
    ... ]), None)
    "foo-1.0-py3-none-any.whl"