new rql pipeline with cache-able security and improved perf
See branch starting at https://bitbucket.org/laurentw/logilab-cubicweb/commits/bf035beaebfe0a21a65f780c63064b234ed7cb8e
and https://bitbucket.org/laurentw/logilab-cubicweb/commits/f28c780526cd905c83fa9bd252df90657fc17fe1 or https://bitbucket.org/laurentw/logilab-cubicweb/commits/0ae6e267c79667de67e0b62b4b428e44201124c3
original ticket : https://www.cubicweb.org/ticket/17254604