FEM new matrix solver types (PaStiX and Pardiso) (#12478)

* Update solver.py
* Update write_step_equation.py
* Update DlgSettingsFemCcx.ui

src/Mod/Fem/Gui/DlgSettingsFemCcx.ui

@@ -343,6 +343,16 @@
             <string>Default</string>
            </property>
           </item>
+          <item>
+           <property name="text">
+            <string>PaStiX</string>
+           </property>
+          </item>
+          <item>
+           <property name="text">
+            <string>Pardiso</string>
+           </property>
+          </item>
           <item>
            <property name="text">
             <string>Spooles</string>

src/Mod/Fem/femsolver/calculix/solver.py

@@ -345,6 +345,8 @@ def add_attributes(obj, ccx_prefs):
     if not hasattr(obj, "MatrixSolverType"):
         known_ccx_solver_types = [
             "default",
+            "pastix",
+            "pardiso",
             "spooles",
             "iterativescaling",
             "iterativecholesky"

src/Mod/Fem/femsolver/calculix/write_step_equation.py

@@ -81,6 +81,10 @@ def write_step_equation(f, ccxwriter):
     # https://forum.freecad.org/viewtopic.php?f=18&t=43178
     if ccxwriter.solver_obj.MatrixSolverType == "default":
         pass
+    elif ccxwriter.solver_obj.MatrixSolverType == "pastix":
+        analysis_type += ", SOLVER=PASTIX"
+    elif ccxwriter.solver_obj.MatrixSolverType == "pardiso":
+        analysis_type += ", SOLVER=PARDISO"
     elif ccxwriter.solver_obj.MatrixSolverType == "spooles":
         analysis_type += ", SOLVER=SPOOLES"
     elif ccxwriter.solver_obj.MatrixSolverType == "iterativescaling":