[FEM] Elmer output material name

- when looking at the Elmer input file 'case.sif' it is extremely helpful to thee also the name of the material
  Since the name is only form info, this does not change the actual simulation

src/Mod/Fem/femsolver/elmer/writer.py

@@ -803,6 +803,7 @@ class Writer(object):
                         "There are two or more materials with empty references.\n\n"
                         "Set for the materials to what solid they belong to.\n"
                     )
+                self._material(name, "Name", m["Name"])
                 if density_needed is True:
                     self._material(
                         name, "Density",
@@ -935,6 +936,7 @@ class Writer(object):
                 if obj.References
                 else self._getAllBodies())
             for name in (n for n in refs if n in bodies):
+                self._material(name, "Name", m["Name"])
                 if "RelativePermittivity" in m:
                     self._material(
                         name, "Relative Permittivity",
@@ -1138,6 +1140,7 @@ class Writer(object):
                 if obj.References
                 else self._getAllBodies())
             for name in (n for n in refs if n in bodies):
+                self._material(name, "Name", m["Name"])
                 if "Density" in m:
                     self._material(
                         name, "Density",
@@ -1564,6 +1567,7 @@ class Writer(object):
                     raise WriteError(
                         "Used material does not specify the necessary 'Density'."
                     )
+                self._material(name, "Name", m["Name"])
                 self._material(
                     name, "Density",
                     self._getDensity(m))

src/Mod/Fem/femtest/data/elmer/box_static_0_mm.sif

@@ -44,6 +44,7 @@ Body 1
 End
 
 Material 1
+  Name = String "Steel-Generic"
   Poisson ratio = Real 0.3
   Youngs Modulus = Real 200000000000.0
 End

src/Mod/Fem/femtest/data/elmer/ccxcantilever_faceload_0_mm.sif

@@ -44,6 +44,7 @@ Body 1
 End
 
 Material 1
+  Name = String "CalculiX-Steel"
   Poisson ratio = Real 0.3
   Youngs Modulus = Real 210000000000.0
 End

src/Mod/Fem/femtest/data/elmer/ccxcantilever_faceload_1_si.sif

@@ -44,6 +44,7 @@ Body 1
 End
 
 Material 1
+  Name = String "CalculiX-Steel"
   Poisson ratio = Real 0.3
   Youngs Modulus = Real 210000000000.0
 End

src/Mod/Fem/femtest/data/elmer/ccxcantilever_nodeload_0_mm.sif

@@ -44,6 +44,7 @@ Body 1
 End
 
 Material 1
+  Name = String "CalculiX-Steel"
   Poisson ratio = Real 0.3
   Youngs Modulus = Real 210000000000.0
 End

src/Mod/Fem/femtest/data/elmer/ccxcantilever_prescribeddisplacement_0_mm.sif

@@ -44,6 +44,7 @@ Body 1
 End
 
 Material 1
+  Name = String "CalculiX-Steel"
   Poisson ratio = Real 0.3
   Youngs Modulus = Real 210000000000.0
 End