[custom channels]: test forward traffic shaper #1877

Job	Run time
backend build on ubuntu-latest	7m 23s
frontend tests on ubuntu-latest	5m 2s
integration test	9m 33s
frontend tests on windows-latest	5m 20s
backend build on windows-latest	7m 10s
check commits	2m 50s
frontend tests on macOS-latest	5m 33s
lint	4m 16s
RPC proto compilation check	9m 16s
check release notes updated	4s
backend build on macOS-latest	7m 18s
unit tests	5m 5s
unit-race	6m 10s
	1h 15m 0s

Provide feedback