interFoam family: Added run-time selectable LTS support

LTS is selected by the ddt scheme e.g. in the
tutorials/multiphase/interFoam/ras/DTCHull case:

ddtSchemes
{
    default         localEuler rDeltaT;
}

LTSInterFoam is no longer needed now that interFoam includes LTS
support.

tutorials/multiphase/interFoam/ras/DTCHull/system/controlDict

@@ -15,7 +15,7 @@ FoamFile
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
-application     LTSInterFoam;
+application     interFoam;
 
 startFrom       startTime;