Improve chigger exodus filename sorting
Improve chigger exodus filename sorting

(closes #15819)

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