Textarea widgets created from the Form Description Editor do not have a default style

[pcdavid]

In the Form Description editor, creating a new widget by DnD from the sidebar normally creates a widget and its corresponding default style.
This is not the case for TextArea widgets.
This is due to AddWidgetEventHandler.createStyle(WidgetDescription) which tries to create the style instance reflexively using assumptions on the name of the style which does not hold for Text Areas:

widgetDescription.eClass().getName() + "Style"

In the case of the Text Area, the names are TextAreaDescription and TextareaDescriptionStyle (note the A vs a).