Add cli for MsgRegisterAccount (#2136)

## Description

Add client cmd for `MsgRegisterAccount`, similar to [inter-tx](https://github.com/cosmos/interchain-accounts-demo/blob/master/x/inter-tx/client/cli/tx.go#L36), but making appropriate changes to make it consistent with other ibc modules.

### Improvements
Maybe we can better have description for the flags as well as client help/usage statements. Do let me know if we can add more clarity here.

closes: #2061

---

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checked off. If any of the checklist items are not applicable, please leave them but
write a little note why.

- [ ] Targeted PR against correct branch (see [CONTRIBUTING.md](https://github.com/cosmos/ibc-go/blob/master/CONTRIBUTING.md#pr-targeting))
- [ ] Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
- [ ] Code follows the [module structure standards](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules/structure.md).
- [ ] Wrote unit and integration [tests](https://github.com/cosmos/ibc-go/blob/master/CONTRIBUTING.md#testing)
- [ ] Updated relevant documentation (`docs/`) or specification (`x/<module>/spec/`)
- [ ] Added relevant `godoc` [comments](https://blog.golang.org/godoc-documenting-go-code).
- [ ] Added a relevant changelog entry to the `Unreleased` section in `CHANGELOG.md`
- [ ] Re-reviewed `Files changed` in the Github PR explorer
- [ ] Review `Codecov Report` in the comment section below once CI passes

(cherry picked from commit 5e78a23)

modules/apps/27-interchain-accounts/client/cli/cli.go

@@ -24,3 +24,20 @@ func GetQueryCmd() *cobra.Command {
 
 	return icaQueryCmd
 }
+
+// NewTxCmd returns the tx commands for the interchain-accounts submodule
+func NewTxCmd() *cobra.Command {
+	icaTxCmd := &cobra.Command{
+		Use:                        "interchain-accounts",
+		Aliases:                    []string{"ica"},
+		Short:                      "interchain-accounts tx subcommands",
+		DisableFlagParsing:         true,
+		SuggestionsMinimumDistance: 2,
+	}
+
+	icaTxCmd.AddCommand(
+		controllercli.NewTxCmd(),
+	)
+
+	return icaTxCmd
+}

modules/apps/27-interchain-accounts/controller/client/cli/tx.go

@@ -0,0 +1,70 @@
+package cli
+
+import (
+	"strings"
+
+	"github.com/cosmos/cosmos-sdk/client"
+	"github.com/cosmos/cosmos-sdk/client/flags"
+	"github.com/cosmos/cosmos-sdk/client/tx"
+	"github.com/spf13/cobra"
+
+	"github.com/cosmos/ibc-go/v5/modules/apps/27-interchain-accounts/controller/types"
+)
+
+const (
+	// The controller chain channel version
+	flagVersion = "version"
+)
+
+// NewTxCmd creates and returns the tx command
+func NewTxCmd() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:                        "controller",
+		Short:                      "ica controller transactions subcommands",
+		DisableFlagParsing:         true,
+		SuggestionsMinimumDistance: 2,
+		RunE:                       client.ValidateCmd,
+	}
+
+	cmd.AddCommand(
+		newRegisterAccountCmd(),
+	)
+
+	return cmd
+}
+
+func newRegisterAccountCmd() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "register [connection-id]",
+		Short: "Register an interchain account on the provided connection.",
+		Long: strings.TrimSpace(`Register an account on the counterparty chain via the 
+connection id from the source chain. Connection identifier should be for the source chain 
+and the interchain account will be created on the counterparty chain. Callers are expected to 
+provide the appropriate application version string via {version} flag. Generates a new 
+port identifier using the provided owner string, binds to the port identifier and claims 
+the associated capability.`),
+		Args: cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			clientCtx, err := client.GetClientTxContext(cmd)
+			if err != nil {
+				return err
+			}
+
+			connectionID := args[0]
+			owner := clientCtx.GetFromAddress().String()
+			version, err := cmd.Flags().GetString(flagVersion)
+			if err != nil {
+				return err
+			}
+
+			msg := types.NewMsgRegisterAccount(connectionID, owner, version)
+
+			return tx.GenerateOrBroadcastTxCLI(clientCtx, cmd.Flags(), msg)
+		},
+	}
+
+	cmd.Flags().String(flagVersion, "", "Controller chain channel version")
+	flags.AddTxFlagsToCmd(cmd)
+
+	return cmd
+}

modules/apps/27-interchain-accounts/module.go

@@ -78,7 +78,7 @@ func (AppModuleBasic) RegisterGRPCGatewayRoutes(clientCtx client.Context, mux *r
 
 // GetTxCmd implements AppModuleBasic interface
 func (AppModuleBasic) GetTxCmd() *cobra.Command {
-	return nil
+	return cli.NewTxCmd()
 }
 
 // GetQueryCmd implements AppModuleBasic interface