-- Control mode given by WHISTCTL overwrites control mode given in
WCONHIST
-- option for termination of run if changed to BHP control in not
implemented. But ParseContext is used to inform the user and make
throwing optional.
For more transactional behaviour and to support MessageContainer in
favour of opm-log, this method now returns an enum describing how the
error should be handled, rather than throwing or no-oping. Throwing is
preserved if ParseContext is configured to do so.