test: total_order_checks: prepare for std::strong_ordering
test: total_order_checks: prepare for std::strong_ordering

Adjust the total_order_check template to work with comparators
returning either int (as a temporary compatibility measure) or
std::strong_ordering (for #1449 safety).

scylladb/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla