feature: Support VPC Lattice integration as frontend service

*To help us debug your issue fill in the basic information below using the options provided*
This is a feature request to support VPC Lattice integration similar to API GW and ALB.

*Serverless Java Container version*: `eg. 1.5`
For both v1 (Spring Boot 2) and v2 (Spring Boot 3.x). Ideally, v2 should be good if v1 is not prioritized.

*Implementations:* `Jersey / Spring / Spring Boot / Spring Boot 2 / Spark`
SpringBoot

*Framework version:* `eg SpringBoot 2.2.6.RELEASE`
Spring Boot 3.x (if feasible, Spring Boot 2)

*Frontend service:* `REST API / HTTP API / ALB`
VPC Lattice

*Deployment method:* `eg SAM, Serverless Framework, Console`
N/A

## Scenario
*Describe what you are trying to accomplish*
Support VPC Lattice as the frontend service. The incoming payload for VPC Lattice is different than API GW. This addition will be a new `RequestSource`, therefore needing a variety of changes related to `AwsProxyRequest`, `AwsProxyResponse`, request POJO, response POJO, request reader, response writer, security context, and more

## Expected behavior
*Describe how you would expect the application to behave*
A Spring Boot application running on a Lambda function should work with VPC Lattice as a request source.

## Actual behavior
*Describe what you are seeing instead*
Currently, VPC Lattice is not supported.