ENH: reduce reliance on stringListOps functions

- findStrings, findMatchingStrings now mostly covered by matching
  intrinsics in wordRe and wordRes.

  Add static wordRes match() and matching() variants

COMP: remove stringListOps include from objectRegistry.H

- was already noted for removal (NOV-2018)

src/finiteVolume/functionObjects/fieldSelections/fieldSelection/fieldSelection.C

@@ -136,7 +136,7 @@ bool Foam::functionObjects::fieldSelection::resetFieldFilters
 
 bool Foam::functionObjects::fieldSelection::read(const dictionary& dict)
 {
-    HashSet<wordRe> fields(0);
+    HashSet<wordRe> fields;
     dict.readEntry("fields", fields);
 
     return resetFieldFilters(fields);