LibJS: Move intrinsics to the realm

Intrinsics, i.e. mostly constructor and prototype objects, but also
things like empty and new object shape now live on a new heap-allocated
JS::Intrinsics object, thus completing the long journey of taking all
the magic away from the global object.
This represents the Realm's [[Intrinsics]] slot in the spec and matches
its existing [[GlobalObject]] / [[GlobalEnv]] slots in terms of
architecture.

In the majority of cases it should now be possibly to fully allocate a
regular object without the global object existing, and in fact that's
what we do now - the realm is allocated before the global object, and
the intrinsics between both :^)

Userland/Libraries/LibJS/Runtime/Intl/DisplayNames.cpp

@@ -115,7 +115,7 @@ ThrowCompletionOr<Value> canonical_code_for_display_names(VM& vm, DisplayNames::
             return vm.throw_completion<RangeError>(ErrorType::IntlInvalidLanguageTag, code);
 
         // c. Return ! CanonicalizeUnicodeLocaleId(code).
-        auto canonicalized_tag = Intl::canonicalize_unicode_locale_id(*locale_id);
+        auto canonicalized_tag = JS::Intl::canonicalize_unicode_locale_id(*locale_id);
         return js_string(vm, move(canonicalized_tag));
     }