Set Application name and type in TransformationResult

[fabiocarvalho777]

This issue depends on #221 and #222.

Set Application name and type in TransformationResult.

Make sure the transformation template API for this feature is very easy to use, ContextAttributeRetriever is too inconvenient and should not be used in this case.

Implementation considerations

Create two reserved transformation context attribute names (see #222), one of them being for the application name, and the other for application type. Once set by the transformation template, they could be easily added to the transformation result object by the transformation engine at the end of the transformation, and before calling transformation listeners.

Storing reserved transformation context attributes

In case of patches and migrations, these reserved attributes are stored at the regular transformation context. In case of upgrades, these reserved attributes must be kept at the global transformation context (see #221).

[fabiocarvalho777]

Closing this issue because #305 is a more generic feature and also covers the use case described here, so it should replace it.

With #305, it is up to the extension developer to decide if application name and type should be persistent or not, and how to retrieve those values, and how to name those attributes.