Support Gatling tests using AWS sigV4 signing

[dlvenable]

Is your feature request related to a problem? Please describe.

The Gatling performance tests could be run against Amazon HTTP endpoints which are authenticated by SigV4. This could allow for running against Amazon OpenSearch Ingestion since this service is making use of Data Prepper. This can also set the groundwork for running tests against other authentication mechanisms such as HTTP Basic Auth and mTLS (if supported in the future).

Describe the solution you'd like

Provide a new property to configure the authentication:

-Dauthentication=aws_sigv4

When set to SigV4 make use of two other properties to configure the region and service name: -Daws_region= and -Daws_service.