Update python VPP reader to handle the existence of FINAL and LATEST symlinks
Update python VPP reader to handle the existence of FINAL and LATEST symlinks

(refs #11087)

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