After the recent fixes 4 tests started failing with the java nodetool
implementation. We are about to ditch the java implementation, but until
we actually do, it is valuable to keep the tests passing with both the
native and java implementation.
So in this patch, these tests are fixed to pass with the java
implementation too.
There is one test, test_help.py, which fails only if run together with
all the tests. I couldn't confirm this 100%, but it seems like this is
due to JMX sending a rouge request on some timer, which happens to hit
this test. I don't think this is worth trying to fix.
Empty histograms are missing some of the members that non-empty
histograms have. The code handling these histograms assumed all required
members are always present and thus error out when receiving an empty
histogram.
Add tests for empty histograms and fix the code handling them to check
for the potentially missing members, instead of making assumptions.
Closesscylladb/scylladb#17816