ENH: use broadcasting streams to distribute uniform file content

BUG: masterUncollatedFileOperation checking of file-size

- used Foam:fileSize check to decide on scheduled/nonBlocking but this
  was being done on all ranks and subsequently broadcast.
  Now avoid unnecessary filesystem access on non-master ranks.

src/OpenFOAM/db/dictionary/functionEntries/codeStream/codeStream.C

@@ -210,7 +210,7 @@ Foam::functionEntries::codeStream::getFunction
 
             off_t mySize = Foam::fileSize(libPath);
             off_t masterSize = mySize;
-            Pstream::scatter(masterSize);
+            Pstream::broadcast(masterSize);
 
             for
             (