feat: use container images in lambda

[bernardobridge]

Description

Reviewing commit by commit is recommended.

Adds --container flag that allows a Lambda test to run using Lambda Container Images. This solves a lot of the current limitations of Lambda:

• No more bundle size limit issues
• Can reuse same Lambda function, making startup time go down to a few seconds
• Publish Metrics will work once again
• Third-party dependencies (npm modules) will now work
• Compatible with Playwright (experimental, so there may be some performance limitations) -> To be addressed later

Notes:

• Change is backwards compatible, and current tests will not be affected (they will use zip-file Lambda by default).
• The main drawback is that Lambda does not support Public ECR images. This means users will need to pull and host our image in their own ECR Private repo, and update it with Artillery updates. We will provide some installation scripts/instructions for users.

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To-do:

• Refactor Lambda to make it easier to keep backwards compatibility (c894486, 2b39f09)
• Implement Lambda using container images opted-in (66498cf)
• Reuse same Docker image for Lambda and Fargate (43d954a, f860db5, 04015c3)
• Reuse same Lambda function (WIP - need to figure out mechanism to determine version)
• Add compatibility with Playwright Engine -> TBA later
• Deprecation notice for regular Lambda support
• Improve console messages when packaging