alias,cache,chunker,crypt: make any created backends be cached to fix rc problems

Before this change, when the above backends created a new backend they
didn't put it into the backend cache.

This meant that rc commands acting on those backends did not work.

This was fixed by making sure the backends use the backend cache.

See: https://forum.rclone.org/t/rclone-rc-backend-command-not-working-as-expected/18834

backend/chunker/chunker.go

@@ -24,6 +24,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/rclone/rclone/fs"
 	"github.com/rclone/rclone/fs/accounting"
+	"github.com/rclone/rclone/fs/cache"
 	"github.com/rclone/rclone/fs/config/configmap"
 	"github.com/rclone/rclone/fs/config/configstruct"
 	"github.com/rclone/rclone/fs/fspath"
@@ -238,15 +239,18 @@ func NewFs(name, rpath string, m configmap.Mapper) (fs.Fs, error) {
 		return nil, errors.New("can't point remote at itself - check the value of the remote setting")
 	}
 
-	baseInfo, baseName, basePath, baseConfig, err := fs.ConfigFs(remote)
+	baseName, basePath, err := fspath.Parse(remote)
 	if err != nil {
 		return nil, errors.Wrapf(err, "failed to parse remote %q to wrap", remote)
 	}
+	if baseName != "" {
+		baseName += ":"
+	}
 	// Look for a file first
 	remotePath := fspath.JoinRootPath(basePath, rpath)
-	baseFs, err := baseInfo.NewFs(baseName, remotePath, baseConfig)
+	baseFs, err := cache.Get(baseName + remotePath)
 	if err != fs.ErrorIsFile && err != nil {
-		return nil, errors.Wrapf(err, "failed to make remote %s:%q to wrap", baseName, remotePath)
+		return nil, errors.Wrapf(err, "failed to make remote %q to wrap", baseName+remotePath)
 	}
 	if !operations.CanServerSideMove(baseFs) {
 		return nil, errors.New("can't use chunker on a backend which doesn't support server side move or copy")
@@ -271,7 +275,7 @@ func NewFs(name, rpath string, m configmap.Mapper) (fs.Fs, error) {
 	// (yet can't satisfy fstest.CheckListing, will ignore)
 	if err == nil && !f.useMeta && strings.Contains(rpath, "/") {
 		firstChunkPath := f.makeChunkName(remotePath, 0, "", "")
-		_, testErr := baseInfo.NewFs(baseName, firstChunkPath, baseConfig)
+		_, testErr := cache.Get(baseName + firstChunkPath)
 		if testErr == fs.ErrorIsFile {
 			err = testErr
 		}