[3/3]: Implement `Consumer` on `chainWatcher` and resolvers #454

Job	Run time
RPC and mobile compilation check	2m 22s
lint code	3m 40s
sample configuration check	50s
Sqlc check	29s
check commits	29m 5s
cross compilation	27m 57s
run unit tests (btcd unit-cover)	27m 34s
check pinned dependencies (google.golang.org/grpc v1.59.0)	4s
run unit tests (unit tags="kvdb_etcd")	27m 30s
run unit tests (unit tags="kvdb_postgres")	27m 32s
check pinned dependencies (github.com/golang/protobuf v1.5.3)	4s
run unit tests (unit tags="kvdb_sqlite")	27m 31s
run macOS itest	36m 34s
run unit tests (btcd unit-race)	27m 35s
run unit tests (unit-module)	1m 20s
check release notes updated	4s
run ubuntu itests (btcd, backend=btcd cover=1)	22m 6s
run ubuntu itests (bitcoind, backend=bitcoind cover=1)	27m 29s
run windows itest	5m 14s
run ubuntu itests (bitcoind-notxindex, backend="bitcoind notxindex")	27m 29s
run ubuntu itests (bitcoind-rpcpolling, backend="bitcoind rpcpolling" cover=1)	27m 27s
run ubuntu itests (bitcoind-etcd, backend=bitcoind dbbackend=etcd)	27m 32s
run ubuntu itests (bitcoind-postgres, backend=bitcoind dbbackend=postgres)	27m 30s
run ubuntu itests (bitcoind-sqlite, backend=bitcoind dbbackend=sqlite)	27m 29s
run ubuntu itests (bitcoind-postgres-nativesql, backend=bitcoind dbbackend=postgres nativesql=true)	27m 28s
run ubuntu itests (bitcoind-sqlite-nativesql, backend=bitcoind dbbackend=sqlite nativesql=true)	27m 22s
run ubuntu itests (neutrino, backend=neutrino cover=1)	26m 32s
finish	3s
	8h 33m 52s

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