feat: Support asynchronous shareable test events

[willyg302]

This feature was added recently to the Lambda console. It works by storing event metadata as an x-metadata OpenAPI extension on the schema's example.

Here we support putting an event with a desired --invocation-type and passing that to a remote invoke (with an explicitly provided invocation type --parameter taking precedence).

Which issue(s) does this change fix?

None.

Why is this change necessary?

To support shareable test events with a saved invocation type.

How does it address the issue?

See above commit message.

What side effects does this change have?

If any shareable test events saved in the console with an Event invocation type were being used for sam remote invoke, they will now start to send Event invokes as if --parameter InvocationType=RequestResponse were passed.

Mandatory Checklist

PRs will only be reviewed after checklist is complete

• Review the generative AI contribution guidelines (GenAI was not used)
• Add input/output type hints to new functions/methods
• Write design document if needed (Do I need to write a design document?)
• Write/update unit tests
• Write/update integration tests (reviewed existing integration tests, no updates should be needed)
• Write/update functional tests if needed
• make pr passes
• make update-reproducible-reqs if dependencies were changed (N/A)
• Write documentation

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.