FEM: rename icon, femmesh to mesh

src/Mod/Fem/Gui/Resources/Fem.qrc

@@ -45,7 +45,7 @@
         <file>icons/FEM_MeshDisplayInfo.svg</file>
         <file>icons/FEM_MeshRegion.svg</file>
         <file>icons/fem-femmesh-result.svg</file>
-        <file>icons/fem-femmesh-to-mesh.svg</file>
+        <file>icons/FEM_FEMMesh2Mesh.svg</file>
         <file>icons/fem-material-fluid.svg</file>
         <file>icons/fem-material-nonlinear.svg</file>
         <file>icons/fem-material-reinforced.svg</file>

src/Mod/Fem/femcommands/commands.py

@@ -628,7 +628,7 @@ class _Mesh2Mesh(CommandManager):
     def __init__(self):
         super(_Mesh2Mesh, self).__init__()
         self.resources = {
-            "Pixmap": "fem-femmesh-to-mesh",
+            "Pixmap": "FEM_FEMMesh2Mesh",
             "MenuText": QtCore.QT_TRANSLATE_NOOP(
                 "FEM_FEMMesh2Mesh",
                 "FEM mesh to mesh"