[optimisation] cwuri need to be in RQL, otherwise it *really* slows down the indexing when cw accesses entity.cw_uri.

Update using entity.cw_attr_cache should be enough, no need to loop over attributes again

Also : ccplugin - generator serves all actions, not split up by type
       es.py - add CUSTOM_ATTRIBUTES mechanism

`indexable_attributes` in yams return only String and Bytes

`esearch` view relies on this attr