AwsBilling - handle additional services when identifying untagged services

[smalers]

The 1.5.2 version includes a way to list properties for services across an entire organization, focusing on high-cost services such as EC2 and VPC. ChatGPT provided the following list of EC2-related services that could be checked for tags:

• instance: EC2 instances - DONE
• volume: EBS volumes - DONE
• network-interface: Network interfaces
• snapshot: EBS snapshots - DONE
• key-pair: Key pairs
• security-group: Security groups
• vpc: VPCs - DONE
• subnet: Subnets
• route-table: Route tables
• internet-gateway: Internet gateways
• natgateway: NAT gateways
• network-acl: Network ACLs

I added a separate table for snapshots because they are stored independent of instances and there can be 0 to many snapshots per EC2 instance. The remaining items may not have high costs so need to evaluate which ones are worth adding.

[smalers]

I added VPN and Elastic IP in version 1.5.3 and updated the original comment. Keep open for now.