Add support for the REST API introduced in Dogtag 10 to the Dogtag CA helper.
Among other features, the REST API provides better error reporting capabilities, which should improve user experience, especially for FreeIPA's automatic certificate renewal.
See also freeipa #3473.
Metadata Update from @jcholast: - Issue set to the milestone: 0.0 NEEDS_TRIAGE
Metadata Update from @rcritten: - Issue assigned to rcritten