Make search on facets work when using JCR as storage

While configuring Nuxeo EP to store datas in JCR, hidden folders as the root of comments are displayed in the UI.
This is due to the fact that lucene is not capable of making negative queries on multiple properties, like ecm:mixinType which stores all the facets a document has.

To fix that, we will create as many attributes as facets defined in the whole application and searches will query these attributes.