ls: introduce and global option to print human-readable sizes and consider it for ls commands

Fixes #1890

fs/config.go

@@ -130,6 +130,7 @@ type ConfigInfo struct {
 	FsCacheExpireDuration  time.Duration
 	FsCacheExpireInterval  time.Duration
 	DisableHTTP2           bool
+	HumanReadable          bool
 }
 
 // NewConfig creates a new config with everything set to the default