Don't use implDetail hypotheses

[JLimperg]

revert may revert implDetail hypotheses if they depend on one of the (regular) hypotheses to be reverted. As a result, tactics which are implemented in terms of revert, such as subst, can inadvertently turn implDetail hypotheses into regular hypotheses. I don't expect this to get fixed in core since core doesn't use implDetail hypotheses in this way, so we should make sure that rules never receive goals with implDetail hypotheses.