daemon/io: configurable idle timeout for incoming TCP connection

The idle timeout was set equal to the timeout for the arrival of the first request after connection had been established. For DNS over TCP it was a half of maximal allowed RTT and it often led to prematurely closing of incoming connection.

added 3 commits

• d9ca7e63...a0670f6b - 2 commits from branch master
• bdd62d40 - daemon: make idle timeout for incoming connection configurable

Compare with previous version

enabled an automatic merge when the pipeline for bdd62d40 succeeds

merged

mentioned in commit a861c4de

/cc @vavrusam