Move some packages into SDK, out of internal

internal/cmd/commands/authmethods/authmethod.go

@@ -8,7 +8,7 @@ import (
 	"github.com/hashicorp/boundary/internal/cmd/base"
 	"github.com/hashicorp/boundary/internal/cmd/common"
 	"github.com/hashicorp/boundary/internal/types/resource"
-	"github.com/hashicorp/vault/sdk/helper/strutil"
+	"github.com/hashicorp/boundary/sdk/strutil"
 	"github.com/kr/pretty"
 	"github.com/mitchellh/cli"
 	"github.com/posener/complete"