[REQ] Option to automatically delete all files/folders in outputDir for openapi gradle plugin

For openapi-generator-gradle-plugin, could you add option to automatically delete all files and folders in outputDir before generating the code files?

The option can be called "cleanOputputDir" (boolean) or such.

openApiGenerate {
    generatorName = "kotlin"
    inputSpec = "$rootDir/specs/petstore-v3.0.yaml".toString()
    outputDir = "$buildDir/generated".toString()
    apiPackage = "org.openapi.example.api"
    invokerPackage = "org.openapi.example.invoker"
    modelPackage = "org.openapi.example.model"
    modelFilesConstrainedTo = [
            "Error"
    ]
    configOptions = [
        dateLibrary: "java8"
    ]
    cleanOutputDir = true
}

Start in the openapi-generator-gradle-plugin module and follow the openApiGenerate configuration entry point to where outputDir is processed before generation. Add the requested cleanOutputDir option, ensuring it removes the output directory contents before files are generated, and verify the Gradle plugin behavior with an appropriate test.