[Maven-Plugin] Comma-separated string parameters should be lists, rather than strings, in the maven plugin

[zmoore-usgs]

Description

In similar vein as #5383 and following in the theme of #5860 this in regards to instantiation-types, type-mappings, language-specific-primitives, additional-properties, and reserved-words-mappings. Currently these are all single-string, comma-separated parameters and when the number of entries grows the lists become unmanageable and hard to read.

Swagger-codegen version

2.2.1, 2.2.2, 2.2.3-SNAPSHOT

Swagger declaration file content or url

This example is taken from #5383 and tweaked to show type-mappings.

<configOptions>
    <type-mappings>json_model=com.mypackage.Model,json_anothermodel=com.mypackage.AnotherModel</type-mappings>
</configOptions>

Command line used for generation

mvn generate-sources

Related issues/PRs

Issues:
#5383
#5860

PRs:

#5384

Suggest a fix/enhancement

The same as was proposed in #5383

(Example modified to show type-mappings)

<configOptions>
    <type-mappings>
        <param>json_model=com.mypackage.Model</param>
        <param>json_anothermodel=com.mypackage.AnotherModel</param>
    </type-mappings>
</configOptions>

[fehguy]

Unfortunately this will be a breaking change for all users of the plugin. Perhaps you can handle the old format as well as the new? I don't know if it's possible, but that's why this hasn't been merged.

You may also want to chime in on #6041 as we will be redoing the interface to access the codegen completely with that PR.