Add multiverse RPC proof courier #1280

Job	Run time
Compilation check	29s
cross compilation	1m 21s
run itests	37s
Format check	19s
run itests postgres	3m 22s
go mod check	34s
Lint check	2m 27s
RPC check	1m 36s
Sqlc check	33s
test vector check	27s
run unit tests (unit-race)	4m 39s
run unit tests (unit-cover)	24s
run unit tests (unit dbbackend=postgres)	1m 29s
	18m 17s

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