[ALL] Return value of `getSchemaType()` is unclear/inconsistent

The interpretation of the return value of DefaultCodegenConfig.getSchemaType() is unclear.

Both the implementation of the method and its documentation suggest that this method should return Swagger types (e.g. integer, file, ...).

However, at least some usages suggest that it should return language types (e.g. int, File, ...).

So far, I've identified two places which such problems:

Problem 1: addImport()

In fromProperty() the field baseType is set like this:

codegenProperty.baseType = getSchemaType(propertySchema);

And then later in addVars() that baseType is used to add an import:

addImport(codegenModel, cp.baseType);

However, addImport() seems to expect a language type, not a swagger type.

Problem 2: toInstantiationType()

In toInstantiationType() the method is used like this:

String inner = getSchemaType(additionalProperties);
return instantiationTypes.get("map") + "<String, " + inner + ">";

This code clearly expects a language type (or Java-like type) - not a Swagger type.

Start with DefaultCodegenConfig.getSchemaType() and its documentation, then trace the usages named in fromProperty(), addVars(), addImport(), and toInstantiationType(). Determine whether the method's contract is Swagger types or language types, and document or align those usages consistently; done means the contract and affected call sites no longer conflict.