Support user-generated RFQ on `tchrpc.SendPayment` #3516

Job	Run time
Docker build check	3m 42s
Format check	26s
Compilation check	40s
cross compilation	4m 20s
run itests	9m 31s
run itests postgres	17m 33s
Lint check	2m 32s
migration version check	12s
RPC check	1m 14s
run LiT tests	12m 23s
sample configuration check	37s
go mod check	21s
Sqlc check	41s
test vector check	45s
run unit tests (unit-race)	11m 15s
run unit tests (unit-cover)	2m 53s
run unit tests (unit dbbackend=postgres)	6m 8s
finish	3s
	1h 15m 16s

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