Enhanced category features

A CategoryEnhancement (which can correspond to a CategoryProperty) can contribute to the index in two possible ways:

1. To each category with data relevant to the enhancement, add this data to the category's token payload, through CategoryEnhancement.getCategoryTokenBytes(). This data will be read during search using CategoryEnhancement.extractCategoryTokenData().
2. To each document which contains categories with data relevant to the enhancement, add a CategoryListTokenizer through CategoryEnhancement.getCategoryListTokenizer() . The CategoryListTokenizer should add a single token which includes all the enhancement relevant data from the categories. The category list token's text is defined by CategoryEnhancement.getCategoryListTermText().