Adds getAdditionalPropertiesIsAnyType to java schema classes

Created by: spacether

Adds getAdditionalPropertiesIsAnyType/setAdditionalPropertiesIsAnyType to java schema classes This is needed if one is generating classes for object schemas. By default object schema includes additionalProperties = AnyType, so if this boolean is False, then one needs to generate a custom class for the object schema. Tests added of X.getAdditionalPropertiesIsAnyType for:

• CodegenModel
• CodegenProperty
• CodegenParameter
• CodegenResponse

This will be used in: https://github.com/OpenAPITools/openapi-generator/pull/8325 And will probably want to be used in go-experimental @wing328 We may want to replace isAdditionalPropertiesTrue with getAdditionalPropertiesIsAnyType @wing328 getAdditionalPropertiesIsAnyType applies to all schema models and is also set to true if the user manually defined an additionalProperties in their spec and its value is any type schema.

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