rust-index: check that the entry bytes are the same in both indexes
This is a temporary measure to show that both the Rust and C indexes are
kept in sync.
Comes with some related documentation precisions.
For comparison of error cases, see `index_entry_binary()` in `revlog.c`.
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"phabricator.uri": "https://phab.mercurial-scm.org/",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}