More QA tests for group operations

This adds QA tests for the SetGroupParams operation, both for CLI and
RAPI. Additionally, it adds tests for add/rename/remove groups via RAPI,
which had not been included in a previous patch series. Finally, it also
tests setting "alloc_policy" (and, for the CLI, "ndparams") at group
creation time.

Signed-off-by: Adeodato Simo <dato@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>