frontend: copy command arguments to output params on client
In commit f554078291d682d59956998af97f7d3066fbe7e7 we stopped copying
command arguments to output params in order to remove redundancies and
reduce API schema in size. Since then, output params were removed from
API schema completely and are reconstructed on the client.
Not including arguments in output params hides failed members from member
commands' CLI output. To fix this, copy arguments to output params again,
but only on the client side.
https://fedorahosted.org/freeipa/ticket/6026
Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>