fs/hash: align hashsum names and update documentation (#5339)

- Unify all hash names as lowercase alphanumerics without punctuation.
- Legacy names continue to work but disappear from docs, they can be depreciated or dropped later.
- Make rclone hashsum print supported hash list in case of wrong spelling.
- Update documentation.

Fixes #5071
Fixes #4841

backend/onedrive/onedrive.go

@@ -93,7 +93,7 @@ var (
 
 // Register with Fs
 func init() {
-	QuickXorHashType = hash.RegisterHash("QuickXorHash", 40, quickxorhash.New)
+	QuickXorHashType = hash.RegisterHash("quickxor", "QuickXorHash", 40, quickxorhash.New)
 	fs.Register(&fs.RegInfo{
 		Name:        "onedrive",
 		Description: "Microsoft OneDrive",