Wt

The setObjectName() function is defined in WObject. However, only in WWebWidget does it have an actual effect.
This means that any WLayout or any other class that directly inherits from WObject has this function, but not always the right effect implemented for it.

This ticket serves to:

1. implement the missing functionality for layouts (so that their container can have a data-object-name)
2. check whether there are more (pseudo)widgets missing this functionality

Note: only widgets that have an actual visual representation will require this functionality. Widgets that only live on the backend with no UI can omit this.