Add a deep copy generic harness to the internal fn package #16884

Job	Run time
Sqlc check	2m 42s
RPC and mobile compilation check	1m 38s
check commits	8m 15s
cross compilation	30m 22s
lint code	3m 45s
sample configuration check	33s
run unit tests (btcd unit-cover)	19m 28s
run unit tests (unit tags="kvdb_etcd")	20m 50s
run ubuntu itests (btcd, backend=btcd cover=1)	29m 47s
run unit tests (unit tags="kvdb_postgres")	19m 42s
run ubuntu itests (bitcoind, backend=bitcoind cover=1)	38m 26s
run unit tests (unit tags="kvdb_sqlite")	18m 59s
check pinned dependencies (google.golang.org/grpc v1.59.0)	5s
run ubuntu itests (bitcoind-notxindex, backend="bitcoind notxindex")	39m 8s
run unit tests (btcd unit-race)	40m 25s
check pinned dependencies (github.com/golang/protobuf v1.5.3)	5s
run ubuntu itests (bitcoind-rpcpolling, backend="bitcoind rpcpolling" cover=1)	38m 59s
run unit tests (unit-module)	1m 3s
run ubuntu itests (bitcoind-etcd, backend=bitcoind dbbackend=etcd)	55m 2s
run ubuntu itests (bitcoind-postgres, backend=bitcoind dbbackend=postgres)	23m 47s
run macOS itest	48m 12s
run ubuntu itests (bitcoind-sqlite, backend=bitcoind dbbackend=sqlite)	41m 52s
check release notes updated	25s
run ubuntu itests (bitcoind-postgres-nativesql, backend=bitcoind dbbackend=postgres nativesql=true)	1h 11m 44s
run ubuntu itests (bitcoind-sqlite-nativesql, backend=bitcoind dbbackend=sqlite nativesql=true)	42m 43s
run windows itest	6m 53s
run ubuntu itests (neutrino, backend=neutrino cover=1)	36m 22s
finish	7s
	10h 41m 19s

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