Do not revalidate authorizations on forced renewal

Do not revalidate authorizations on forced renewal

This commit introduces a new cli argument `--force-validation` which,
when used in combination with `--force` ignores valid domain
authorizations and forces a revalidation.

This has been implemented since at least LE seems to have changed some
behavior on valid authorizations. Only the previously validated
authorization-type is reusable, causing dehydrated to error out when
changing from recently validated authorization types while still trying
to force-renew certificates for whatever reason (e.g. changing algorithms).