Move wxMSW wxTextCtrl::GetDefaultAttributes() to wxTextCtrlBase.

This commit doesn't introduce any changes in the control behaviour, it simply
moves the existing method to the base class because it is not MSW-specific.

Also implement wxTextCtrlBase::GetClassDefaultAttributes() because if a class
implements GetDefaultAttributes() it should implement it as well.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62803 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/textctrl.h

@@ -705,6 +705,18 @@ public:
        wxTextEntry::SetValue(value);
     }
 
+    // wxWindow overrides
+    virtual wxVisualAttributes GetDefaultAttributes() const
+    {
+        return GetClassDefaultAttributes(GetWindowVariant());
+    }
+
+    static wxVisualAttributes
+    GetClassDefaultAttributes(wxWindowVariant variant = wxWINDOW_VARIANT_NORMAL)
+    {
+        return GetCompositeControlsDefaultAttributes(variant);
+    }
+
 protected:
     // override streambuf method
 #if wxHAS_TEXT_WINDOW_STREAM