[REQ] spring generator generate RequestParams objects

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

I'd like to see a model class generated for request parameters.

https://docs.spring.io/spring-framework/reference/web/webmvc/mvc-controller/ann-methods/modelattrib-method-args.html

probable this should take some options, as it may not be for controllers, basically the option not to add spring mvc annotations. Really I want it so that we don't forget any. In addition generating the static strings for endpoints would still be nice.

openApiGenerate {
    generatorName = "spring"
    library = "spring-boot"
    inputSpec = "$projectDir/src/main/resources/openapi.json".toString()
    outputDir = layout.buildDirectory.dir("generated/sources/openapi").get().toString()
    configOptions.putAll([
        openApiNullable        : "false",
        generateApis           : "false",
        generateSupportingFiles: "false",
        serializationLibrary   : "jackson",
        interfaceOnly          : "true",
        annotationLibrary      : "none",
        documentationProvider  : "none",
    ])

The request targets the spring generator and its openApiGenerate configuration, with spring-boot selected in the example. Review the generator’s existing model and request-parameter generation paths first; done should include generated RequestParams model classes, an option for controller annotations, and the requested static endpoint strings where supported.