optimisation of egression for multiple async insert

[titanproger]

Hi clickhouse team!
We are using clickhouse cloud and recently we need optimise how much data downloaded from CH cloud.

We use Ch to insert different events using async inserts.
So sometimes we insert a small amount of records with one query, thanks to Async insert we can do small inserts.

But with each insert a noticeable amount of meta data is downloaded .
So in log i see some times 6 kb downloaded and only a few bytes uploaded to CH.

After reviewing server code i see there is different protocol version supported.
TCPHandler.cpp

Feature request: allow client to select preferable protocol version.

So for my example it will reduce downloaded size from 6KB to around 200 bytes (depending on table schema)

[titanproger]

PR: #1553