feat: add project id support for scoutfs backend

The scoutfs filesystem allows setting project IDs on files and
directories for project level accounting tracking. This adds the
option to set the project id for the following:
create bucket
put object
put part
complete multipart upload

The project id will only be set if all of the following is true:
- set project id option enabled
- filesystem format version supports projects (version >1)
- account project id > 0

cmd/versitygw/scoutfs.go

@@ -26,6 +26,7 @@ import (
 var (
 	glacier          bool
 	disableNoArchive bool
+	setProjectID     bool
 )
 
 func scoutfsCommand() *cli.Command {
@@ -66,6 +67,12 @@ move interfaces as well as support for tiered filesystems.`,
 				EnvVars:     []string{"VGW_CHOWN_GID"},
 				Destination: &chowngid,
 			},
+			&cli.BoolFlag{
+				Name:        "projectid",
+				Usage:       "set project id on newly created buckets, files, and directories to client account ProjectID",
+				EnvVars:     []string{"VGW_SET_PROJECT_ID"},
+				Destination: &setProjectID,
+			},
 			&cli.BoolFlag{
 				Name:        "bucketlinks",
 				Usage:       "allow symlinked directories at bucket level to be treated as buckets",
@@ -114,6 +121,7 @@ func runScoutfs(ctx *cli.Context) error {
 	opts.DisableNoArchive = disableNoArchive
 	opts.VersioningDir = versioningDir
 	opts.ValidateBucketNames = disableStrictBucketNames
+	opts.SetProjectID = setProjectID
 
 	be, err := scoutfs.New(ctx.Args().Get(0), opts)
 	if err != nil {