F2 Rename dialog needs selected object context (i.e. Model name, Object location & Metaclass type)

In Web Service Operation Editor, using F2 to rename the selected Input Variable renames the Operation instead. Right click - Rename works fine, but many users are used to using F2 to rename. If we do not choose to support F2 when we have selected a variable in Input Variables, or an Operation in the Operations tree, then we should make sure it does nothing. If we do want to support F2 for renaming, then it should rename the selected object, not the Operation.