infinitepush: add tests for `hg pull -r <rev>`
This patch adds test for `hg pull -r <rev>` when the infinitepush extension is
not present on the client side and the server by defaults pushes all the
incoming push to bundlestore.
As the tests show, if a the changeset was applied to the server, that can be
pulled, but if a changeset is in the bundlestore we cannot pull that yet. We
should support that.
Differential Revision: https://phab.mercurial-scm.org/D2998