Support for VPC endpoints

[NoeHoyos]

I wonder if it is possible to add support for VPC url endpoints to fence_aws. It checks against the standard service url, for example ec2.amazonaws.com, but if traffic needs to be kept inside the VPC it would be better to check against the EC2 VPC endpoint like for example vpce-abc123-xyz789.ec2.us-east-1.vpce.amazonaws.com. This will benefit setups where internet access is restricted.
Thank you,
Noe