JSON logging support

AWS Lambda offers support for both [plain-text and JSON format logs](https://docs.aws.amazon.com/lambda/latest/dg/monitoring-cloudwatchlogs-logformat.html).

Lambda exposes this configuration via the `AWS_LAMBDA_LOG_FORMAT` environment variable. It's currently missing from the [environment variable documentation](https://docs.aws.amazon.com/lambda/latest/dg/configuration-envvars.html#configuration-envvars-runtime) (see case 175226052300866), but the variable appears to be set to either `Text` or `JSON` depending on customer configuration.

There's a couple of aspects to supporting this:
* Runtime-intrinsic logs (e.g. anything that's `Write-Host '[RUNTIME-<...>'`)
* Customer logs that use:
* Unstructured string-only logs (`Write-Debug`, `-Verbose`, `-Warning`)
* Unstructured partially-formatted logs (`Write-Host`)
* Structured logs via `Write-Information`
* Implicit log events (e.g. ErrorRecords generated from parser errors)

Commencez par lire la documentation AWS Lambda liée sur la journalisation et retracez la relation entre AWS_LAMBDA_LOG_FORMAT et la gestion existante par le runtime de Write-Host, Write-Debug, -Verbose, -Warning, Write-Information et des ErrorRecords implicites. Le travail est considéré comme terminé lorsque les comportements JSON et texte brut sont définis et implémentés pour les événements de journalisation intrinsèques au runtime, du client, structurés et implicites.

Rédigé par le modèle d'indexation à partir du texte de l'issue.