Properly toggle editor state when calling editId() on the server

Properly toggle editor state when calling editId() on the server
(#18287)

Ensure isEditorActive() returns false if editItem(...) has been called
but the
editor has not yet been opened, as it should according to javadoc

isRendered() requires that the editor fields are marked as dirty when
they are
made visible on the client (isEditorActive() changes state)

Change-Id: I7123332c6769f7a7f6b00852bddc8dbbaa311754