Move WriteBroadcaster to separate package as BroadcastWriter

Docker-DCO-1.1-Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com> (github: LK4D4)
Benchmark for BroadcastWriter

Docker-DCO-1.1-Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com> (github: LK4D4)
BroadcastWriter refactoring

It became slightly faster and lighter
possibly fixes #5923 problems

Docker-DCO-1.1-Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com> (github: LK4D4)
Merge pull request #6821 from LK4D4/broadcast_writer_refactor

Broadcast writer refactor