LPS-42541 Add default portlet titles to the Look And Feel data
LPS-42541 Display default portlet title if there is no custom title
LPS-42541 Do not remove empty portlet titles (make behavior consistent with UpdateTitleAction)
LPS-42541 Remove title from Portlet Preferences if it is the same as the default one
LPS-42541 Do not fallback to the title of the default language or empty string in case of custom titles. If there is no custom title then the default language specific title will be used