[REQ] easier and more consistent package name configuration

With openapi-generator-plugin 4.3.0, there are currently 4 package name configuration options:

1. packageName
2. apiPackage
3. modelPackage
4. invokerPackage

In configOptions, you can even specify a basePackage, adding more options for confusion...
Note that even the name of the options is not consistent;)
It is rarely needed to tweak each and every single option individually, I guess most projects will just want to define one name that is then suffixed with api and model, respectively.

So I'd propose to:

• use packageName synonymously with basePackage and use that as a base name for all other package names by default, unless explicitly overridden with the existing options
• deprecate all other package options and introduce apiPackageSuffix and modelPackageSuffix etc. to fine tune those if really needed (default should be api, model,… instead of the current ...apiPackage which is redundantly including "package" in the name itself
• don't default to openapi.generator.maven.plugin since this won't make sense for any project except for this one - a better default would be to use the groupId+artifactId from the POM of the project that uses openapi-generator

Start by tracing how packageName, basePackage, apiPackage, modelPackage, and invokerPackage are handled in the openapi-generator-plugin 4.3.0 configuration. Review the plugin's Maven project defaults, including groupId and artifactId handling, before deciding how suffixes and deprecated options should interact. Done means one consistent base package, configurable suffixes, preserved overrides, and an appropriate project-derived default.