decomposePar, reconstructPar: Do all regions simultaneously

DecomposePar and reconstructPar now interleave the processing of
multiple regions. This means that with the -allRegions option, the
earlier times are completed in their entirety before later times are
considered. It also lets regions to access each other during
decomposition and reconstruction, which will be important for
non-conformal region interfaces.

To aid interpretation of the log, region prefixing is now used by both
utilities in the same way as is done by foamMultiRun.

DecomposePar has been overhauled so that it matches reconstructPar much
more closely, both in terms of output and of iteration sequence. All
meshes and addressing are loaded simultaneously and each field is
considered in turn. Previously, all the fields were loaded, and each
process and addressing set was considered in turn. This new strategy
optimises memory usage for cases with lots of fields.

applications/utilities/parallelProcessing/reconstructPar/fvFieldReconstructor.C

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2022 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2023 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -66,8 +66,7 @@ Foam::fvFieldReconstructor::fvFieldReconstructor
     procMeshes_(procMeshes),
     faceProcAddressing_(faceProcAddressing),
     cellProcAddressing_(cellProcAddressing),
-    faceProcAddressingBf_(faceProcAddressingBf),
-    nReconstructed_(0)
+    faceProcAddressingBf_(faceProcAddressingBf)
 {
     forAll(procMeshes_, proci)
     {
@@ -93,4 +92,26 @@ Foam::fvFieldReconstructor::fvFieldReconstructor
 }
 
 
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+bool Foam::fvFieldReconstructor::reconstructs
+(
+    const IOobjectList& objects,
+    const HashSet<word>& selectedFields
+)
+{
+    bool result = false;
+
+    #define DO_FV_FIELDS_TYPE(Type, nullArg)                                   \
+        result = result                                                        \
+         || reconstructs<VolField<Type>::Internal>(objects, selectedFields)    \
+         || reconstructs<VolField<Type>>(objects, selectedFields)              \
+         || reconstructs<SurfaceField<Type>>(objects, selectedFields);
+    FOR_ALL_FIELD_TYPES(DO_FV_FIELDS_TYPE)
+    #undef DO_FV_FIELDS_TYPE
+
+    return result;
+}
+
+
 // ************************************************************************* //