LiveTable header filters display objects from hidden documents by default

See the related discussion on IRC : https://botbot.me/freenode/xwiki/2018-01-24/?msg=96097441&page=1

The common use case for this bug is when a user creates an AWM and then tries to integrate pages of this AWM in the filter of a LiveTable. As the AWM creates a <MyAppName>Template document that contains an instance of the AWM class, this document will show up in the LT filter.

Reproduction steps

1. Create a test AWM app
2. create an entry
3. Edit http://localhost:8080/xwiki/bin/view/test/ and set the smallest LT definition (see snippet below)
4. observe the LT

{{velocity}}
#set ($columnsProperties = {})
#set ($options = {'className': 'test.Code.testClass', 'translationPrefix': 'test.livetable.'})
#set ($columns = ['doc.title', 'doc.location', 'doc.date', 'doc.author', '_actions', 'shortText1'])
#livetable('test' $columns $columnsProperties $options)
{{/velocity}}

Expected

Only the created entry is listed

Actual

A hidden page is listed in addition to the created entry