STYLE: use ""_deg user-literal for degrees to radians conversion

ENH: add degToRad() multiplier (useful for scalar fields)

- use degToRad() functions throughout instead of scattered local solutions

applications/utilities/mesh/conversion/datToFoam/datToFoam.C

@@ -122,7 +122,7 @@ int main(int argc, char *argv[])
     fileName pointsFile(runTime.constantPath()/"points.tmp");
     OFstream pFile(pointsFile);
 
-    scalar a(degToRad(0.1));
+    const scalar a = 0.1_deg;
     tensor rotateZ =
         tensor
         (

applications/utilities/mesh/conversion/kivaToFoam/readKivaGrid.H

@@ -419,7 +419,7 @@ if (pFaces[WEDGE].size() && pFaces[WEDGE][0].size())
     {
         // Distribute the points to be +/- 2.5deg from the x-z plane
 
-        scalar tanTheta = Foam::tan(degToRad(2.5));
+        const scalar tanTheta = Foam::tan(2.5_deg);
 
         SLList<face>::iterator iterf = pFaces[WEDGE][0].begin();
         SLList<face>::iterator iterb = pFaces[WEDGE][1].begin();

applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/conformalVoronoiMesh/conformalVoronoiMeshConformToSurface.C

@@ -33,10 +33,10 @@ License
 using namespace Foam::vectorTools;
 
 const Foam::scalar Foam::conformalVoronoiMesh::searchConeAngle
-    = Foam::cos(degToRad(30));
+    = Foam::cos(30.0_deg);
 
 const Foam::scalar Foam::conformalVoronoiMesh::searchAngleOppositeSurface
-    = Foam::cos(degToRad(150));
+    = Foam::cos(150.0_deg);
 
 
 // * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * * //