FEM: solver frame work, move get custom dir to snake_case

src/Mod/Fem/femsolver/run.py

@@ -193,7 +193,7 @@ def _getCustomDir(solver):
 
 
 def _getCustomBase(solver):
-    path = settings.getCustomDir()
+    path = settings.get_custom_dir()
     if not os.path.isdir(path):
         raise DirectoryDoesNotExistError("Invalid path")
     return path

src/Mod/Fem/femsolver/settings.py

@@ -144,7 +144,7 @@ def get_write_comments(name):
 
 
 # ******** working directory parameter ***********************************************************
-def getCustomDir():
+def get_custom_dir():
     param_group = FreeCAD.ParamGet(_GENERAL_PARAM)
     return param_group.GetString("CustomDirectoryPath")