Add ELB Context to HttpApiV2Request

[driverpt]

Serverless Java Container version: 1.9

Implementations: Micronaut

Framework version: Micronaut AWS master branch

Frontend service: HTTP API / ALB

Deployment method: SAM`

Scenario

Describe what you are trying to accomplish
Implement micronaut-projects/micronaut-aws#1317

Expected behavior

Payload V2 working with both HTTP API and ALB

Actual behavior

Cannot differentiate HTTP API from ALB Request via requestContext

Steps to reproduce

N/A

Full log output

N/A

[driverpt]

cc @msailes

[deki]

Released as part of version 1.9.1.