Deprecate use of data-parsoid

Parsoid has never intended for this attribute to be for public
consumption, and is soon removing it from many cases.

This patch converts all uses of data-parsoid to more appropriate
attributes and adds a few tests along the way.

The is one remaining location using data-parsoid, the
PlaceholderExtractor which generates references to redlinked pages
in NS_FILE. There is currently no other information output for these
so it has no other choice.

Change-Id: Ifbe3c3386165a36bfe6dbd7c49d08cb92630998d
Merge "Deprecate use of data-parsoid"