common-cli: add possibility to have command duplicates

Motivation:
In situations, where a bean that provides a command used by a single
cell twice (HA leader election for different activities, for example),
then we need a way how to identify such command

Modification:
Add a new command annotation `CommandPrefix` that can be used to
annotate String field of a class to resolve such command conflict.

Result/Example:

A possibility to instantiate multiple beans of the same type and command
set.

```
public class HAServiceLeadershipManager {

    @CommandPrefix
    private final String serviceName;

}
```

```
 admin > \s PnfsManager help

  ...
chimera-fs-maintenance ha get role
chimera-fs-maintenance ha release leadership
chimera-fs-maintenance ha show participants
  ...

pnfsmanager ha get role
pnfsmanager ha release leadership
pnfsmanager ha show participants

```
Acked-by: Albert Rossi
Acked-by: Lea Morschel
Acked-by: Paul Millar
Target: master
Require-book: no
Require-notes: yes

modules/common-cli/src/main/java/dmg/util/command/CommandPrefix.java

@@ -0,0 +1,29 @@
+/* dCache - http://www.dcache.org/
+ *
+ * Copyright (C) 2023 Deutsches Elektronen-Synchrotron
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package dmg.util.command;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.FIELD)
+public @interface CommandPrefix {
+
+}

modules/common-cli/src/main/java/org/dcache/util/cli/AnnotatedCommandScanner.java

@@ -5,6 +5,7 @@
 import com.google.common.collect.Maps;
 import com.google.common.reflect.TypeToken;
 import dmg.util.command.Command;
+import dmg.util.command.CommandPrefix;
 import java.io.Serializable;
 import java.lang.reflect.Constructor;
 import java.util.List;
@@ -53,7 +54,22 @@ private Class<? extends Callable<? extends Serializable>> cast(Class<?> clazz) {
                               cast(commandClass).getDeclaredConstructor(
                                     commandClass.getDeclaringClass());
                         constructor.setAccessible(true);
-                        commands.put(asList(command.name().split(" ")),
+
+                        String prefix = null;
+                        for(var field : obj.getClass().getDeclaredFields()) {
+                            if (field.isAnnotationPresent(CommandPrefix.class)) {
+                                try {
+                                    field.setAccessible(true);
+                                    prefix = (String)field.get(obj);
+                                    break;
+                                } catch (IllegalAccessException e) {
+                                    throw new RuntimeException(e);
+                                }
+                            }
+                        }
+
+                        var commandName =  prefix == null ? command.name() : prefix + " " + command.name();
+                        commands.put(asList(commandName.split(" ")),
                               new AnnotatedCommandExecutor(obj, command, constructor));
                     } catch (NoSuchMethodException e) {
                         throw new RuntimeException(