Added Parsoid support for nowiki stripping in args of {{#tag:ext|...}}

• This patch relies on extensions setting a flag in their Parsoid ext. config indicating that a specific tag handler needs nowikis stripped from #tag arguments.
  
  In the #tag parser function implementation, Parsoid's SiteConfig is looked up to see if nowiki needs to be stripped.

• This need not be limited to nowikis, but to support extension use in {{#tag:ext|...}} more generally, we would need to either (a) implement the #tag parser function in Parsoid natively; OR (b) find a way to call Parsoid from extensionSubstitution
  
  Soln (a) needs Parsoid to support parser functions natively.
  
  If this general support becomes necessary, a later patch can generalize this appropriately.

Bug: T272939
Bug: T299103
Depends-On: I6a653889afd42fefb61daefd8ac842107dce8759
Depends-On: I56043e0cb7d355a3f0d08e429bb1dbba6acb4fba
Change-Id: I614153af67b5a14f33b7dfc04bd00dd9e03557d0