Dynamic route sorting

[ahopkins]

Currently it is this:

        return (
            child.dynamic,
            len(child._children),
            key,
            bool(child.group and child.group.regex),
            type_ * -1,
        )

It should be:

        return (
            child.dynamic,
            len(child._children),
            bool(child.group and child.group.regex),
            type_ * -1,
            key,
        )

... so that the variable name is the last tie breaker