While measuring #17149 with this test some changes were applied, here they are
- keep initial_tablets number in output json's parameters section
- disable auto compaction
- add control over the amount of sstables generated for --bypass-cache case
Closesscylladb/scylladb#17473
* github.com:scylladb/scylladb:
perf_simple_query: Add --memtable-partitions option
perf_simple_query: Disable auto compaction
perf_simple_query: Keep number of initial tablets in output json