hgweb: remove one-off routing for file?style=raw
Now that both functions are using the same API, we can unify how
the command is called and perform command-specific behavior in the
command itself instead of in the high-level router.
Differential Revision: https://phab.mercurial-scm.org/D2788
#require docutils gettext
$ $TESTDIR/check-gendoc sv
checking for parse errors