XWIKI-9309: Also search in attachments when type is DOCUMENT
* Use a different query boost (default index fields and their boost factor) depending on the selected results type (i.e. depending on what we search for: documents, attachments, objects, object properties)
* Use by default (for free text search) only the index fields that are indexed as 'text_general' (and equivalent). It doesn't make sense to search free text in fields that are not analized (i.e. that keep the exact value for faceting).

(cherry picked from commit 40789fde611c1fde0bcf5583563d6fc079803644)