An Azure Bastion module that can be added to a virtual network

[glennmusa]

Benefit/Result/Outcome
Automated deployment of a Bastion host and its dependent components (subnet, PIP)

Description
Taking a virtual network as input, I should be able to include a Bastion module that creates the correct and valid subnet in that virtual network and creates its required public IP address:

Helpful links:

• https://docs.microsoft.com/en-us/azure/bastion/bastion-overview
• https://docs.microsoft.com/en-us/azure/bastion/tutorial-create-host-portal
• https://docs.microsoft.com/en-us/azure/bastion/quickstart-host-portal
• https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/bastion_host

Acceptance Criteria

• A new standalone "bastion" module that can be reused by any TF configuration with a virtual network
• The module takes a dependency on a virtual network as input
• The module takes a dependency on a valid subnet for that virtual network as input
• The subnet created within the module is named "AzureBastionSubnet"
• The subnet created within the module is /27 or larger