templates: split getgraphnode() body into two functions
getgraphnodecurrent() is checking if the node is currently checked out and
getgraphnodesymbol() is checking properties that have more to do with the
stored data and the DAG.
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}