First implementation of 1D radial case. Only charged particles taked

into account (as in 1D Cartesian case).

The 1D Cathode example case has been modified, having now 2 input files:
  - inputCart.json: Used for Cartesian coordinates
  - inputRad.json:  Used for Radial coordinates

Pusher is a Boris pusher but without z direction.

src/modules/mesh/2DCyl/moduleMeshCyl.f90

@@ -360,7 +360,7 @@ MODULE moduleMeshCyl
 
     !Computes element local stiffness matrix
     PURE FUNCTION elemKQuad(self) RESULT(ke)
-      USE moduleConstParam
+      USE moduleConstParam, ONLY: PI
       IMPLICIT NONE
 
       CLASS(meshVolCylQuad), INTENT(in):: self