[ECR Public] [request]: Add VPC (PrivateLink) support for public repo push and pull

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**Tell us about your request**
What do you want us to build?
Add VPC endpoints for Amazon ECR Public

**Which service(s) is this request for?**
ECR Public

**Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?**
What outcome are you trying to achieve, ultimately, and why is it hard/impossible to do right now? What is the impact of not having this problem solved? The more details you can provide, the better we'll be able to understand and solve the problem.
Push and pull images from ECR Public without leaving the Amazon network.

**Are you currently working around this issue?**
How are you currently solving this problem?
Pull from an ECR public repo into an ECR private repo and then use ECR private VPC endpoints. However anonymous pulls cannot be used, and we also have to configure IAM policies for access.

**Additional context**
Anything else we should know?

**Attachments**
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