[BUG] [Spring] [Spring-Boot] Exploded query parameters are not correctly serialized in controller

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

When generating code with an exploded query parameter, the spring generator with the spring-boot library does not correctly resolve the supplied parameters. Some experimentation suggests that the serialization is using the name of the field in the Java object, not the name of the field in the OpenAPI specification.

openapi-generator version

6.4.0

OpenAPI declaration file content or url

https://github.com/GregDThomas/openapi-generator-spring-boot-example/blob/main/specs/explode-query-parameter.yaml

Generation Details

Using the OpenAPI Generator Gradle Plugin with

    generatorName = "spring"
    library = 'spring-boot'

Steps to reproduce

See the sample project at https://github.com/GregDThomas/openapi-generator-spring-boot-example and more specifically the tests in ExampleControllerTest

Specifically -

• the fields in the exploded object that match the name of the field in the POJO (someCamelString) are correctly serialized.
• the fields in the exploded object that do no match the name of the field in the POJO are not correctly serialized.
  -- some-kebab-string / someKebabString
  -- some_snake_string / someSnakeString

Related issues/PRs

Suggest a fix

Start with the sample project's specs/explode-query-parameter.yaml and ExampleControllerTest, then reproduce generation with the spring generator and spring-boot library. Trace the generated controller and parameter handling for fields whose OpenAPI names use kebab-case or snake_case. Done means exploded query fields serialize using their specification names as well as matching Java field names.