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/devrpc_active.go

@@ -0,0 +1,62 @@
+//go:build dev
+// +build dev
+
+package commands
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/lightningnetwork/lnd/lncfg"
+	"github.com/lightningnetwork/lnd/lnrpc"
+	"github.com/lightningnetwork/lnd/lnrpc/devrpc"
+	"github.com/urfave/cli"
+)
+
+// devCommands will return the set of commands to enable for devrpc builds.
+func devCommands() []cli.Command {
+	return []cli.Command{
+		{
+			Name:        "importgraph",
+			Category:    "Development",
+			Description: "Imports graph from describegraph JSON",
+			Usage:       "Import the network graph.",
+			ArgsUsage:   "graph-json-file",
+			Action:      actionDecorator(importGraph),
+		},
+	}
+}
+
+func getDevClient(ctx *cli.Context) (devrpc.DevClient, func()) {
+	conn := getClientConn(ctx, false)
+	cleanUp := func() {
+		conn.Close()
+	}
+	return devrpc.NewDevClient(conn), cleanUp
+}
+
+func importGraph(ctx *cli.Context) error {
+	ctxc := getContext()
+	client, cleanUp := getDevClient(ctx)
+	defer cleanUp()
+
+	jsonFile := lncfg.CleanAndExpandPath(ctx.Args().First())
+	jsonBytes, err := os.ReadFile(jsonFile)
+	if err != nil {
+		return fmt.Errorf("error reading JSON from file %v: %v",
+			jsonFile, err)
+	}
+
+	jsonGraph := &lnrpc.ChannelGraph{}
+	err = lnrpc.ProtoJSONUnmarshalOpts.Unmarshal(jsonBytes, jsonGraph)
+	if err != nil {
+		return fmt.Errorf("error parsing JSON: %w", err)
+	}
+	res, err := client.ImportGraph(ctxc, jsonGraph)
+	if err != nil {
+		return err
+	}
+
+	printRespJSON(res)
+	return nil
+}