Add saltenv whitelist/blacklist to hgfs

This adds the same feature recently added for gitfs. In addition, it fixes a couple issues with gitfs showing files/dirs from blacklisted envs in ``cp.list_master`` and ``cp.list_master_dirs``, which would lead to problems with ``file.managed`` and ``file.recurse`` states thinking that the files existed but being unable to serve them.

Additionally, this pull request also simplifies how per-remote params are handled (a change recently made in gitfs), and adds per-remote support for ``hgfs_branch_method`` and ``hgfs_base``.