discovery: prevent recomputing info about server and outgoing changesets
We already iterate over the outgoing.missing above and lookup repo for them. So
let's reuse info calculated at that time instead of recomputing that again.
Also we calculate the set of remotebranches by doing set(remotemap), so let's
reuse that again.
Upcoming patches will clean things a bit more.
Differential Revision: https://phab.mercurial-scm.org/D6144
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}