Instead, porting over all users to use the newly created
Origin::create_opaque factory function. This also requires porting
over some users of Origin to avoid default construction.
This is required to store Content Security Policies, as their
Directives are implemented as subclasses with overridden virtual
functions. Thus, they cannot be stored as generic Directive classes, as
it'll lose the ability to call overridden functions when they are
copied.
