This copies the Parsoid extension code into includes/VEParsoid
to allow a "one extension, zero-configuration" install of
VisualEditor for MW's LTS release. The Parsoid code has been
re-namespaced (`VEParsoid` instead of `MWParsoid`) to avoid
autoloader conflicts if you actually install Parsoid as an
extension (as we do in Wikimedia production). Similarly, we
arrange that the ServiceWiring and RestRoutes configurations
are skipped unless running in zeroconf mode, to avoid
conflicts with the Parsoid extension.
This import matches Parsoid commit b30f223.
Bug: T248343
Change-Id: Ic63ce40f59c4be8f4fdc5f9ac17798353fc86866
