[REQ] Add a new property "baseDataType" for containers

[noordawod]

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

For arrays and maps, the dataType property currently holds the complete definition of the container, as in:

List<ModelType>
Map<ModelType>

There is a property for the container type (baseType), but there's no property for the type itself: ModelType

Describe the solution you'd like

Add a new property in the generator, specifically when dealing with containers, that holds the generic type of the list/map. I propose to call it baseDataType.

Additional context

This is needed for Dart, as an example, when generating code for the constructors.

class AClass {
  AClass({
    this.prop = const <AnotherClass>[],    // this line cannot be created today.
  });

  final List<AnotherClass> prop;
}

[kuhnroyal]

From my experience this is usually the property complexType.

      "openApiType" : "array",
      "baseName" : "tags",
      "complexType" : "Tag",
      "getter" : "getTags",
      "setter" : "setTags",
      "dataType" : "List<Tag>",
      "datatypeWithEnum" : "List<Tag>",
      "name" : "tags",
      "defaultValue" : "const []",
      "defaultValueWithParam" : " = data.tags;",

[noordawod]

I'll check it, thanks @kuhnroyal!