It may be of interest to copy WTreeTableNode items text content. These
cannot be selected with the mouse for copy to clipboard. The text is
here shown read-only in an extended auto-replaced WLineEdit.
In-place editing with a popup if user is allowed in app config file.
User must of course manage at least a private key. User identities of
target key may be selectively chosen. Optionally, certification may be
exportable and non-revocable.
