Update identity functionality:
    
        - Add identity_renderPostActions and identity_renderLastActions to
          handle post-rendition and last-rendition actions respectively.
          
        - Update identity_renderBase to start using
          identity_renderPostActions and identity_renderLastActions
          functions.
    
        - Update post-rendition and last-rendition actions to remove
          definition of FILE and ACTION variables from them. Such
          variables are already defined by identity_renderBase and
          identity_renderPostActions and identity_renderLastActions. We
          only need to reuse them, there is no need to redefine them from
          themselves.