rust-matchers: add support for `exactmatcher` in `dirstate.status`
`exactmatcher` is the name in the Python implementation and corresponds to
`FileMatcher` in Rust.
Differential Revision: https://phab.mercurial-scm.org/D7531
%include map-cmdline.default
[templates]
changeset = '{cset}{branches}{bookmarks}{tags}{lphase}{parents}{luser}{ldate}{summary}\n'
changeset_verbose = '{cset}{branches}{bookmarks}{tags}{lphase}{parents}{luser}{ldate}{lfiles}{lfile_copies_switch}{description}\n'