itest+lntest: migrate lntemp to lntest

This commit performs the takeover that `lntemp` is now promoted to be
`lntest`, and the scaffolding is now removed as all the refactoring is
finished!

lntest/rpc/chain_notifier.go

@@ -0,0 +1,44 @@
+package rpc
+
+import (
+	"github.com/lightningnetwork/lnd/lnrpc/chainrpc"
+)
+
+// =====================
+// ChainClient related RPCs.
+// =====================
+
+type ConfNtfnClient chainrpc.ChainNotifier_RegisterConfirmationsNtfnClient
+
+// RegisterConfirmationsNtfn creates a notification client to watch a given
+// transaction being confirmed.
+func (h *HarnessRPC) RegisterConfirmationsNtfn(
+	req *chainrpc.ConfRequest) ConfNtfnClient {
+
+	// RegisterConfirmationsNtfn needs to have the context alive for the
+	// entire test case as the returned client will be used for send and
+	// receive events stream. Thus we use runCtx here instead of a timeout
+	// context.
+	client, err := h.ChainClient.RegisterConfirmationsNtfn(
+		h.runCtx, req,
+	)
+	h.NoError(err, "RegisterConfirmationsNtfn")
+
+	return client
+}
+
+type SpendClient chainrpc.ChainNotifier_RegisterSpendNtfnClient
+
+// RegisterSpendNtfn creates a notification client to watch a given
+// transaction being spent.
+func (h *HarnessRPC) RegisterSpendNtfn(req *chainrpc.SpendRequest) SpendClient {
+	// RegisterSpendNtfn needs to have the context alive for the entire
+	// test case as the returned client will be used for send and receive
+	// events stream. Thus we use runCtx here instead of a timeout context.
+	client, err := h.ChainClient.RegisterSpendNtfn(
+		h.runCtx, req,
+	)
+	h.NoError(err, "RegisterSpendNtfn")
+
+	return client
+}