Allow convergence on zeroth nl iteration for ReferenceResidualProblem
Allow convergence on zeroth nl iteration for ReferenceResidualProblem

I don't understand why the original author made it so that
convergence could not be achieved on the zeroth nl iteration.
This removes once of the principal advantages that I see of
ReferenceResidualProblem in that it can recognize essentially
that we've achieved a steady-state condition and/or that it
doesn't make any sense to keep iterating because the variables
are converged with respect to reference quantities.

Refs #14004

laagesen/moose,sapitts/moose,lindsayad/moose,harterj/moose,idaholab/moose,andrsd/moose,dschwen/moose,nuclear-wizard/moose,nuclear-wizard/moose,idaholab/moose,nuclear-wizard/moose,sapitts/moose,laagesen/moose,jessecarterMOOSE/moose,SudiptaBiswas/moose,milljm/moose,andrsd/moose,milljm/moose,nuclear-wizard/moose,jessecarterMOOSE/moose,andrsd/moose,milljm/moose,lindsayad/moose,lindsayad/moose,harterj/moose,sapitts/moose,idaholab/moose,lindsayad/moose,idaholab/moose,harterj/moose,jessecarterMOOSE/moose,laagesen/moose,dschwen/moose,bwspenc/moose,lindsayad/moose,idaholab/moose,bwspenc/moose,jessecarterMOOSE/moose,harterj/moose,laagesen/moose,SudiptaBiswas/moose,sapitts/moose,dschwen/moose,andrsd/moose,bwspenc/moose,jessecarterMOOSE/moose,SudiptaBiswas/moose,dschwen/moose,bwspenc/moose,harterj/moose,SudiptaBiswas/moose,milljm/moose,bwspenc/moose,dschwen/moose,milljm/moose,laagesen/moose,SudiptaBiswas/moose,andrsd/moose,sapitts/moose