Process deleted node correctly

[SviatlanaHlukhava]

When we try to get deleted question or topic we should get "Not found" message and page should be reloaded.

[SviatlanaHlukhava]

When we try to edit deleted topic or question we should to add it and reload topicTree/questionsPage.

These problems are needed to be decided.

1. When we try to edit topic that was deleted with parent topic we can loose questions from deleted topics because can't take it from UI.
2. When we try to edit question that was deleted with parent topic we can't get information about parent topic and it's not clear where this question should be added.