sqldb: `InvoiceDB` implementation #13178

Job	Run time
check commits	5m 48s
lint code	4m 40s
cross compilation	8m 31s
check pinned dependencies (google.golang.org/grpc v1.56.3)	5s
check pinned dependencies (github.com/golang/protobuf v1.5.3)	4s
check release notes updated	5s
RPC and mobile compilation check	1m 40s
sample configuration check	37s
Sqlc check	34s
run ubuntu itests (btcd, backend=btcd)	38m 34s
run windows itest	40m 7s
run unit tests (btcd unit-cover)	16m 10s
run ubuntu itests (bitcoind, backend=bitcoind)	49m 7s
run unit tests (unit tags="kvdb_etcd")	18m 42s
run ubuntu itests (bitcoind-notxindex, backend="bitcoind notxindex")	48m 30s
run unit tests (unit tags="kvdb_postgres")	17m 3s
run ubuntu itests (bitcoind-rpcpolling, backend="bitcoind rpcpolling")	47m 54s
run unit tests (unit tags="kvdb_sqlite")	16m 3s
run ubuntu itests (bitcoind-etcd, backend=bitcoind dbbackend=etcd)	1h 6m 56s
run unit tests (btcd unit-race)	33m 38s
run ubuntu itests (bitcoind-postgres, backend=bitcoind dbbackend=postgres)	1h 21m 0s
run unit tests (unit-module)	46s
run ubuntu itests (bitcoind-sqlite, backend=bitcoind dbbackend=sqlite)	52m 33s
run ubuntu itests (bitcoind-postgres-nativesql, backend=bitcoind dbbackend=postgres nativesql=true)	1h 21m 54s
run ubuntu itests (bitcoind-sqlite-nativesql, backend=bitcoind dbbackend=sqlite nativesql=true)	50m 42s
run ubuntu itests (neutrino, backend=neutrino)	47m 7s
	12h 8m 50s

Provide feedback