this is one of the changes to reduce the usage of integer based generation
test. in future, we will need to expand the test to exercise the UUID
based generation, or at least to be neutral to the underlying generation's
identifier type. so, to remove the helpers which only accept `generation_type::int_t`
would helps us to make this happen.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
bd3e8d0460