Add page space and parent support in livetable options

Support for page space and page parent should be added to livetable options.
Currently the only easy way to list all pages of a space is including page Main.Dashboard in the home page of a space, but using being able to have a livetable is clearly better.
Parent is a standard XWiki field so it also makes sense to have it in the options.

#set($options = { ...
                  "space":"$MySpace",
                  "parent" : "$AnyPage",
                   ...
                   ...        })

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