tutorials: Updated the momentum transport model type selection

renaming the legacy keywords
    RASModel -> model
    LESModel -> model
    laminarModel -> model

which is simpler and clear within the context in which they are specified, e.g.

RAS
{
    model               kOmegaSST;
    turbulence          on;
    printCoeffs         on;
}

rather than

RAS
{
    RASModel            kOmegaSST;
    turbulence          on;
    printCoeffs         on;
}

The old keywords are supported for backward compatibility.

tutorials/multiphase/interFoam/RAS/DTCHull/constant/turbulenceProperties

@@ -19,7 +19,7 @@ simulationType  RAS;
 
 RAS
 {
-    RASModel        kOmegaSST;
+    model           kOmegaSST;
 
     turbulence      on;