Add audit log entries for user roles (#19040)

* Refactor audit log schema

* Add audit log entries for user roles

app/models/ip_block.rb

@@ -27,6 +27,10 @@ class IpBlock < ApplicationRecord
 
   after_commit :reset_cache
 
+  def to_log_human_identifier
+    "#{record.ip}/#{record.ip.prefix}"
+  end
+
   class << self
     def blocked?(remote_ip)
       blocked_ips_map = Rails.cache.fetch(CACHE_KEY) { FastIpMap.new(IpBlock.where(severity: :no_access).pluck(:ip)) }