Add support to list type custom rules and managed rules for the WAF

[SazniMohamed]

Purpose

Support both Map and List input formats for custom and managed WAF rules in Front Door Firewall Policy

This update enhances the azurerm_cdn_frontdoor_firewall_policy Terraform module by introducing support for both map and list input types for custom and managed WAF rules. This makes the module more flexible and compatible with different data structures used in varying contexts (e.g., dynamic generation or static inputs).