[VPC Endpoint + Endpoint Service] - [Cross-Region Private Link] - support for this new feature

### Name of the resource

AWS::EC2::VPCEndpoint

### Resource name

_No response_

### Description

This is actually a request for 2 services, both AWS::EC2::VPCEndpoint and AWS::EC2::VPCEndpointService. I created the request under endpoint because it is the heavier lift of the 2 when it comes to deploying resources via cloud formation (for example, specifying DNS entries based on the endpoint requires the endpoint to be created successfully).

The request is to support the new AWS Private Link cross-region support as detailed here: https://aws.amazon.com/blogs/networking-and-content-delivery/introducing-cross-region-connectivity-for-aws-privatelink/

Essentially, VPCEndpointService needs to allow specifying the supported regions for the service AND VPCEndpoint needs to support specifying the service region.

The article above outlines exactly what is required for setup in the console, which today is the only way to accomplish this.

### Other Details

_No response_

Start by reading the linked AWS PrivateLink cross-region announcement and compare its console setup with AWS::EC2::VPCEndpoint and AWS::EC2::VPCEndpointService. Confirm the required supported-regions setting for the service and service-region setting for the endpoint; done means both resources can be configured through CloudFormation for the documented cross-region setup.

Written by the indexing model from the issue text.