Unify the feature editor header (title) in Modeler

Feature headers are headers designed for different feature editors: Branding, Document Schema, Document Type, Life Cycle, Process Definition, Page Provider, etc. Most of them have a unified style:

EditorName myFeature

But it's not always the case, sometimes we use colon ':' as separator, sometimes we use space ' ', sometimes the editor name is not defined—we use the name its base class "Feature". This should be unified to provide a better user-experience. You can see the screenshot in attachements for more information.

This header is configured under GWT, via overridden methods of abstract method AbstractFeatureEditor#getEditorTitle.