cmd/lncli: move commands and export

We want to export some of our CLI code to re-use in other projects. But
in Golang you cannot import code from a `main` package.
So we need to move the actual code into its own package and only have
the `func main()` in the `main` package.

cmd/commands/cmd_state.go

@@ -0,0 +1,47 @@
+package commands
+
+import (
+	"context"
+
+	"github.com/lightningnetwork/lnd/lnrpc"
+	"github.com/urfave/cli"
+)
+
+var getStateCommand = cli.Command{
+	Name:     "state",
+	Category: "Startup",
+	Usage:    "Get the current state of the wallet and RPC",
+	Description: `
+	Get the current state of the wallet. The possible states are:
+	 - WAITING_TO_START: node is waiting to become the leader in a cluster
+	   and is not started yet.
+	 - NON_EXISTING: wallet has not yet been initialized.
+	 - LOCKED: wallet is locked.
+	 - UNLOCKED: wallet was unlocked successfully, but RPC server isn't ready.
+	 - RPC_ACTIVE: RPC server is active but not fully ready for calls.
+	 - SERVER_ACTIVE: RPC server is available and ready to accept calls.
+	`,
+	Flags:  []cli.Flag{},
+	Action: actionDecorator(getState),
+}
+
+func getState(ctx *cli.Context) error {
+	ctxb := context.Background()
+	client, cleanUp := getStateServiceClient(ctx)
+	defer cleanUp()
+
+	req := &lnrpc.SubscribeStateRequest{}
+	stream, err := client.SubscribeState(ctxb, req)
+	if err != nil {
+		return err
+	}
+
+	// Get a single state, then exit.
+	resp, err := stream.Recv()
+	if err != nil {
+		return err
+	}
+
+	printRespJSON(resp)
+	return nil
+}