bookmarks: introduce listbinbookmarks()
`bookmarks` bundle2 part will work with binary nodes. To avoid unnecessary
conversions between binary and hex nodes let's add `listbinbookmarks()` that
returns binary nodes. For now this function is a copy-paste of
listbookmarks(). In the next patch this copy-paste will be removed.
Test issue2761
$ hg init
$ touch to-be-deleted
$ hg add
adding to-be-deleted
$ hg ci -m first
$ echo a > to-be-deleted
$ hg ci -m second
$ rm to-be-deleted
$ hg diff -r 0
Same issue, different code path
$ hg up -C
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ touch does-not-exist-in-1
$ hg add
adding does-not-exist-in-1
$ hg ci -m third
$ rm does-not-exist-in-1
$ hg diff -r 1