Add compression settings

[mshustov]

Compression helps reduce the transferred data size at the cost of some CPU overhead. It might be beneficial to enable compression in environments with low network bandwidth.
The client doesn't support extended configuration for the compression settings. The binary switch is sufficient.
Settings:

interface Compression {
  // enable compression for the data transferred from ClickHouse to a client. Default value: true.
  read: boolean;
  // enable compression for the data transmitted from a client to the ClickHouse server. Default value: false.
  write: boolean
}

We need some performance benchmarks to justify enabling compression by default.

[mshustov]

implemneted in #16
I'm leaving the issue open to re-evaluating defaults after performance benchmarking.