Implement the support for adhoc commands

We have two basic example commands. But it’s not entirely finished because
there are some error checks that we don’t do.

ref #2521

src/xmpp/xmpp_component.hpp

@@ -1,6 +1,7 @@
 #ifndef XMPP_COMPONENT_INCLUDED
 # define XMPP_COMPONENT_INCLUDED
 
+#include <xmpp/adhoc_commands_handler.hpp>
 #include <network/socket_handler.hpp>
 #include <xmpp/xmpp_parser.hpp>
 #include <bridge/bridge.hpp>
@@ -177,6 +178,11 @@ public:
    * Send a result IQ with the gateway disco informations.
    */
   void send_self_disco_info(const std::string& id, const std::string& jid_to);
+  /**
+   * Send the list of all available ad-hoc commands to that JID. The list is
+   * different depending on what JID made the request.
+   */
+  void send_adhoc_commands_list(const std::string& id, const std::string& requester_jid);
   /**
    * Send an iq version request
    */
@@ -231,6 +237,7 @@ private:
 
   static unsigned long current_id;
 
+  AdhocCommandsHandler adhoc_commands_handler;
   XmppComponent(const XmppComponent&) = delete;
   XmppComponent(XmppComponent&&) = delete;
   XmppComponent& operator=(const XmppComponent&) = delete;