### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

We are using the `Authorization` header for routing purposes

```
 "authorization: AWS4-HMAC-SHA256 <...>"
```

https://github.com/localstack/localstack/issues/5770

### Expected Behavior

Use a custom header to avoid causing confusion with backend integrations

### How are you starting LocalStack?

With a `docker run` command

### Steps To Reproduce

Run a custom HTTP integration without authorisation

### Environment

```markdown
- OS: 
- LocalStack:
```


### Anything else?

No
elif result[0] == "states" in auth_header or host.startswith("states."):
        result = "stepfunctions", config.service_port("stepfunctions")
    elif "route53." in host:
        result = "route53", config.service_port("route53")
    elif result[0] == "monitoring":
        result = "cloudwatch", config.service_port("cloudwatch")
    elif result[0] == "email":
        result = "ses", config.service_port("ses")
    elif result[0] == "execute-api" or ".execute-api." in host:
        result = "apigateway", config.service_port("apigateway")
    elif target.startswith("Firehose_"):
        result = "firehose", config.service_port("firehose")
    elif target.startswith("DynamoDB_"):
        result = "dynamodb", config.service_port("dynamodb")
    elif target.startswith("DynamoDBStreams") or host.startswith("streams.dynamodb."):
        
        result = result_before = "dynamodbstreams", config.service_port("dynamodbstreams")
    elif result[0] == "EventBridge" or target.startswith("AWSEvents"):
        result = "events", config.service_port("events")
    elif target.startswith("ResourceGroupsTaggingAPI_"):
        result = "resourcegroupstaggingapi", config.service_port("resourcegroupstaggingapi")
    elif result[0] == "resource-groups":
        result = "resource-groups", config.service_port("resource-groups")
    elif result[0] == "es" and path is not None and not path.startswith("/2015-01-01/"):
        
        
        
        result = "opensearch", config.service_port("opensearch")
    return result[0], result_before[1] or result[1], path, host
def extract_service_name_from_auth_header(headers: Dict) -> Optional[str]: