Created a template to deploy API Gateway + Serverless endpoint

[shinglyu]

Issue #, if available: N/A

Description of changes:
This adds a new template to automate the deployment of models in the Amazon SageMaker model registry to SageMaker Serverlss Endpoints with a API Gateway for real-time inference. This project is derived from the built-in MLOps template for model deployment but uses serverless inference endpoints + API Gateway to provide a REST API.

@dgallitelli kindly agreed to review this PR. This will serve as an example used in a upcoming workshop material.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[dgallitelli]

Missing permissions to update a running project for the LaunchRole created in the template. Suggest reverting to default product launch role (however note PR#39) or add to your custom one.

Approved for merge once fixed.

[dgallitelli]

Found a DataCaptureUploadPath issue when deploying as well. Some leftovers from real-time/asynchronous endpoints?

[dgallitelli]

Tested, and approved for merging. Thanks @shinglyu for your contribution! @kirit93 I don't have write access, can you merge this PR? Feel free to test as you see fit.

[kirit93]

Please take a look at the template for GitLab. The expectation for contributions is to automate the creation of the Service Catalog Product. The main readme in this repo provides a CFN template to create a Portfolio and each project template should have a CFN template to create a Product within that folder. Please update this PR so a user can leverage this template with a single CFN template.

[dgallitelli]

@kirit93 isn't it already like this? This PR follows the example of the serverless endpoint template, providing a single CFN file. The README file explains this also.

[shinglyu]

If I do a git diff upstream/main on my local computer (upstream is this aws-samples/sagemaker-custom-packages-templates repo), I can see that file as well:

[shinglyu]

@kirit93 I think I know why, the file https://github.com/aws-samples/sagemaker-custom-project-templates/pull/37/files#diff-13890f9e344706cad5a42295d1638cf9e82e1f17f65787ae8851fed6d9878f89 is too long so is hidden by default by GitHub. That's why it's not obvious to see at first glance.