Setup vnet peering for MongoDB with the virtual network as part of application setup

[einari]

Automate the following: https://www.mongodb.com/docs/mongocli/v1.16/reference/atlas/networking-peering-create-azure/

Service Principal automation https://www.pulumi.com/registry/packages/azuread/api-docs/serviceprincipal/

VNet Peering automation https://www.pulumi.com/registry/packages/mongodbatlas/api-docs/networkpeering/#example-with-azure