[rfq]: add validation to `AddAssetBuyOrder` and `AddAssetSellOrder` RPCs #3433

Job	Run time
Docker build check	3m 44s
Format check	29s
cross compilation	4m 51s
Compilation check	45s
run itests	49s
run itests postgres	47s
migration version check	13s
Lint check	2m 41s
go mod check	27s
RPC check	1m 16s
run LiT tests	13m 20s
sample configuration check	37s
Sqlc check	2m 40s
test vector check	51s
run unit tests (unit-race)	7m 28s
run unit tests (unit-cover)	2m 38s
run unit tests (unit dbbackend=postgres)	5m 26s
finish	8s
	49m 10s

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