XEP-0060: Add pubsub#publish_node_full

[Ppjet6]

List thread: https://mail.jabber.org/pipermail/standards/2023-March/039211.html

[Ppjet6]

<revision>                                                                                    
  <version>1.25.0</version>                                                                   
  <date>2023-03-22</date>                                                                     
  <initials>mw, pep</initials>                                                                
  <remark>                                                                                    
    <ul>                                                                                      
      <li><p>Add data model informational text in Implementation Notes.</p></li>              
      <li><p>Provide a way for a PubSub service to tell a client when a node is full.</p></li>
      <li><p>Clarify behaviour and current usage of the 'pubsub#itemreply' option.</p></li>
      <li><p>Fix spec approver</p></li>                                                       
    </ul>                                                                                     
  </remark>                                                                                   
</revision>                                                                                   

[iNPUTmice]

accepted by council