[core] Improve cold startime

1. Effectively and simply measure cold start time to establish a baseline on a couple of scenario (Hello World, Soto + DynamoDB, AWS SDK + DynamoDB for example)
2. Explore improvements provided by using the static linux musl SDK or the static Amazon Linux 2023 SDK
3. Explore improvements brought by reducing the binary size)
4. Document how to achieve minimum cold start time (this probably won't be the default for the archive plugin)

This is related to
- benchmark: https://github.com/swift-server/swift-aws-lambda-runtime/issues/577
- compile for musl: https://github.com/swift-server/swift-aws-lambda-runtime/issues/332 (and update the [CI](https://github.com/swift-server/swift-aws-lambda-runtime/issues/547)
- document deployment of OCI images: https://github.com/swift-server/swift-aws-lambda-runtime/issues/193 and https://github.com/swift-server/swift-aws-lambda-runtime/issues/485
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