Support shared test events in CloudFormation

### Name of the resource

AWS::Lambda::Function

### Resource name

_No response_

### Description

Lambda has launched support for shared test events ([link](https://aws.amazon.com/about-aws/whats-new/2022/03/aws-lambda-console-test-events/)).

Please add CloudFormation support, so that we can automate creation of shared test events.

### Other Details

Launch announcement: https://aws.amazon.com/about-aws/whats-new/2022/03/aws-lambda-console-test-events/
Documentation: https://docs.aws.amazon.com/lambda/latest/dg/testing-functions.html#creating-shareable-events

Start by reading the linked Lambda shared test events announcement and documentation, then investigate how this repository tracks CloudFormation resource coverage for AWS::Lambda::Function. No repository files or tests are named in the issue; done means defining and implementing CloudFormation support for creating shared Lambda test events.

Written by the indexing model from the issue text.