CPropertyNameValidator: Initialize all member variables

Provides a consistent initial state.

src/Editor/CPropertyNameValidator.h

@@ -10,7 +10,7 @@ class CPropertyNameValidator : public QValidator
     Q_OBJECT
 
     /** The property being validated against */
-    IProperty* mpProperty;
+    IProperty* mpProperty = nullptr;
 
     /** String to use to override the type name. If empty, the property's normal type name is used. */
     QString mTypeNameOverride;