Adding duplicate Feature does not revert Feature pane

[lvanvugt]

When executing scenario 095 in which a duplicate feature is being tried to create an error is validly thrown that the feature already exists, but the Feature pane is not refreshed and the textbox with the duplicate feature name remains.

Test Scenarios

No.	Feature	Scenario
0095	Adding Feature	Adding duplicate Feature

in atdd-test-scenarios-and-results.xlsx

Was found while testing #102

[DavidFeldhoff]

The backend returns that the change isn't valid. Marton is going to change the UI side that the value is cleared after leaving the field (or on a similar event) if the change wasn't valid.

[martonsagi]

UI change implemented. The textbox value will revert to empty value in case of unsuccessful savechanges action.