Prepare for custom channels (lnd v0.18.4-beta) #1901

Job	Run time
frontend tests on ubuntu-latest	4m 56s
integration test	21m 31s
frontend tests on windows-latest	5m 47s
check commits	8m 28s
backend build on ubuntu-latest	6m 56s
frontend tests on macOS-latest	5m 33s
backend build on windows-latest	6m 50s
lint	3m 37s
RPC proto compilation check	9m 11s
backend build on macOS-latest	6m 58s
check release notes updated	3s
unit tests	5m 6s
unit-race	6m 6s
	1h 31m 2s

Provide feedback