Remove usages of deprecated LocalStack code features in AWS replicator

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Currently, the AWS Replicator extension is using some parts of the LocalStack codebase which is deprecated and about to be removed:
- `localstack.utils.server.http2_server.run_server` which is based on `Quart` (which has been superseded by the underlying `hypercorn` quite some time ago).
- `localstack.aws.api.HttpRequest` which should be replaced with `localstack.http.Request`.

These usages are currently blocking the following PRs in `localstack/localstack`:
- https://github.com/localstack/localstack/pull/9754
- https://github.com/localstack/localstack/pull/9757

It would be best to refactor the AWS Replicator Extension such that it spawns the Auth Proxy a new `Gateway` (and migrate the logic to a implement a LocalStack handlerchain handler).
/cc @lukqw @whummer @thrau

Beginne damit, die AWS Replicator-Verwendungen von localstack.utils.server.http2_server.run_server und localstack.aws.api.HttpRequest zu lokalisieren, und prüfe anschließend die verlinkten localstack PRs auf den Kompatibilitätskontext. Erledigt ist die Aufgabe, wenn diese veralteten Verwendungen entfernt und der Auth Proxy in Richtung eines Gateway und eines LocalStack handlerchain handler migriert wurde.

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