Consider adding ClickBench

[alexey-milovidov]

https://github.com/ClickHouse/ClickBench

The main advantage of ClickBench is that it has a good balance between being simple (this is how it has >50 DBMS) and still stressful enough (it is used not only for DBMS, but for hardware tests, as the tests max out the CPU, memory bandwidth, and IO).

Note: I'm the author of ClickBench (but it's doubtful whether I will have time to contribute it directly here, so it is just a proposal).