What are the allowed values for firewall application rule "web_categories"?

- If the issue is to do with Azure CLI 2.0 in-particular, create an issue here at [Azure/azure-cli](https://github.com/Azure/azure-cli/issues)

### Related command

### Extension name (the extension in question)

### Description of issue (in as much detail as possible)

-----

I've done a lot of searching but not found the allowed values for the azurerum firewall application rules "web_categories". When I just use the text examples under the "Category" column provided by Microsoft Learn documentation (https://learn.microsoft.com/en-us/azure/firewall/web-categories), I get the error from Terraform:

AdditionalInfo=[{"Message":"The request is invalid.","ModelState":{"resource":["{\"Status\":\"Failed\",\"Error\":{\"Code\":\"FirewallPolicyApplicationRuleInvalidWebCategory\",\"Message\":\"**Firewall Policy Application Rule WebCategoriesRule web category 'Child abuse images' is invalid**\",\"Target\":null}}"]}}]