CMake: Don't filter out new keys

Previously, if you have a filter set in the CMake Settings
variable list, adding a new one would immediately hide it,
as the text filter hides the "<UNSET>" key. This made it look
like the adding failed.

With this change, new Variables are always shown so
they stay editable to user.

Change-Id: I9c2eb7f9983b23e1cd3aa50f589142551caaf56f
Reviewed-by: Cristian Adam <cristian.adam@qt.io>

src/plugins/cmakeprojectmanager/configmodel.cpp

@@ -546,6 +546,9 @@ QVariant ConfigModelTreeItem::data(int column, int role) const
     if (role == ConfigModel::ItemIsInitialRole) {
         return dataItem->isInitial ? "1" : "0";
     }
+    if (role == ConfigModel::ItemIsUserNew) {
+        return dataItem->isUserNew ? "1" : "0";
+    }
 
     auto fontRole = [this]() -> QFont {
         QFont font;