ENH: Tidied surface film mapping functionality

...PatchFields/derived/mappedField/mappedFieldFvPatchField.C

...atic/SurfaceFilmModel/SurfaceFilmModel/SurfaceFilmModel.C

...atic/SurfaceFilmModel/SurfaceFilmModel/SurfaceFilmModel.H

...ic/SurfaceFilmModel/ThermoSurfaceFilm/ThermoSurfaceFilm.C

...ic/SurfaceFilmModel/ThermoSurfaceFilm/ThermoSurfaceFilm.H

...upled/filmPyrolysisTemperatureCoupledFvPatchScalarField.C

...yCoupled/filmPyrolysisVelocityCoupledFvPatchVectorField.C

src/regionModels/regionModel/regionModel/regionModel.C

src/regionModels/regionModel/regionModel/regionModel.H

src/regionModels/regionModel/regionModel/regionModelI.H

...gionModels/regionModel/regionModel/regionModelTemplates.C

...lmWallFunction/alphatFilmWallFunctionFvPatchScalarField.C

...FilmWallFunction/mutkFilmWallFunctionFvPatchScalarField.C

...s/surfaceFilmModels/thermoSingleLayer/thermoSingleLayer.C