Shell: Added a helper function isHelpRequest() (#7380)

* Added a helper function `isHelpRequest()`

* also handles combined short flags like -lh or -hl

* Created handleHelpRequest() helper function

encapsulates both:
Checking for help flags
Printing the help message

* Limit to reasonable length (2-4 chars total) to avoid matching long options like -verbose

weed/shell/command_fs_rm.go

@@ -39,6 +39,11 @@ func (c *commandFsRm) HasTag(CommandTag) bool {
 }
 
 func (c *commandFsRm) Do(args []string, commandEnv *CommandEnv, writer io.Writer) (err error) {
+
+	if handleHelpRequest(c, args, writer) {
+		return nil
+	}
+
 	isRecursive := false
 	ignoreRecursiveError := false
 	var entries []string