Test pattern module integration with Azure Landing Zone module

`networks` defined in these modules are designed to be peered with external Azure networks (see Azure/terraform-azurerm-avm-ptn-epic#11). The `epic` module itself is designed to be deployed into an Azure Landing Zone (ALZ) deployed using [these Azure Verified Modules (AVM)](https://learn.microsoft.com/en-us/azure/cloud-adoption-framework/ready/landing-zone/deploy-landing-zones-with-terraform). Users may peer to hub virtual networks not deployed via these modules but we need to enable the easiest possible path to the ALZ AVMs.