dictionary scalar lookup: simplified syntax using the type templated lookup function

Replaced
    readScalar(dict.lookup("name"))
with
    dict.lookup<scalar>("name")

etc/codeTemplates/functionObject/FUNCTIONOBJECT.C

@@ -51,7 +51,7 @@ Foam::functionObjects::FUNCTIONOBJECT::FUNCTIONOBJECT
 :
     fvMeshFunctionObject(name, runTime, dict),
     wordData_(dict.lookupOrDefault<word>("wordData", "defaultWord")),
-    scalarData_(readScalar(dict.lookup("scalarData"))),
+    scalarData_(dict.lookup<scalar>("scalarData")),
     labelData_(dict.lookup<label>("labelData"))
 {
     read(dict);