Trace filter 4 + fixes for download.v2 (#1907)

* Introduce TraceCallSet bucket and fill it up

* Fix compile

* Reset TraceCallSet

* Add database.verbosity

* Warn about dropped messages

* Unwind for call traces

* Fixes for headers download

* Fix for the slow stage 3

* Remove wakeup channels

* Permit system for peer load balancing

* Reduce aggressiveness

Co-authored-by: Alex Sharp <alexsharp@Alexs-MacBook-Pro.local>
Co-authored-by: Alexey Sharp <alexeysharp@Alexeys-iMac.local>