cache: relax requirement for replace rule command

cache: relax requirement for replace rule command

No need for full cache, this command relies on the rule handle which is
not validated from userspace. Cache requirements are similar to those
of add/create/delete rule commands.

This speeds up incremental updates with large rulesets.

Extend tests/coverage for rule replacement.

Fixes: 01e5c6f0ed03 ("src: add cache level flags")
Tested-by: Eric Garver <eric@garver.life>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>