Using underscores in `prefix` breaks the flow for deploying iglu_server for Azure

[emielver]

When you have a prefix value with underscores in Azure, e.g. snowplow_test, everything will run as expected in the base module. However, in the iglu_server module you then run into the following error after trying to terraform apply:

│ Error: domain_name_label must contain only lowercase alphanumeric characters, numbers and hyphens. It must start with a letter, end only with a number or letter and not exceed 63 characters in length
│ 
│   with module.iglu_lb.azurerm_public_ip.ip,
│   on .terraform/modules/iglu_lb/main.tf line 33, in resource "azurerm_public_ip" "ip":
│   33:   domain_name_label = "${var.name}-${random_uuid.ip_domain_name_label.result}"
│ 

This error also persists when then trying to run terraform destroy to restart everything, which can be solved by using the terraform state rm module.iglu_lb.random_uuid.ip_domain_name_label command to clean it up.