Update ContributionCancelActions to also handle 'failed'

Update ContributionCancelActions to also handle 'failed'

The failed action has no discernable difference from the no-longer-used cancel action. The cancel action had some minor refactoring
done to work through the conclusion that the call to addRecurLineItems was never reached in a meaningful way
but I think we can skip all that & see that fail is not functionally different to cancel & just deprecate the function.

At this point we are very close to simply removing the last core handling for failed & cance & making the extension visible.

The only thing I can see that still needs checking in the 2 functions still to be removed is the handling of
is_override & override_date is tested - which I will do as a follow up