largefiles: pass current transaction to `lfdirstate.write()`
Right now, the largefile dirstate is not included in transaction which makes
things complex. Next patch will add code to do so, so let's make it mandatory to
pass current transaction and pass from all existing callers.
Differential Revision: https://phab.mercurial-scm.org/D11610
#require docutils gettext
$ $TESTDIR/check-gendoc ru
checking for parse errors