dirstate: wrap repository change in appropriate context in `test-context`
We need the `wlock` (to add files), the `lock` (to commit), a `transaction` (to
commit) and a `changing_files` context (to add files).
Strictly speaking, we could let the commit take the `lock` and create a
`transaction`, but it seems more consistent that way.
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"phabricator.uri": "https://phab.mercurial-scm.org/",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}