AVM2: Partially support parentAllowsChild when domains match

[adrian17]

Partially addresses #14455 .

The window now kinda works, though it's slow, leaks memory (known unload() issues) and sometimes hangs after throwing:

2025-02-14T22:19:50.642618Z ERROR ruffle_core::avm2::events: Error dispatching event EventObject { type: "getUserEnvironment", class: src.com.gaiaonline.FishTank.events::DataConnectorEvent, ptr: 0x2a5c77646f0 } to handler FunctionObject(FunctionObject { ptr: 0x2a5c5b73e00, name: "src.com.gaiaonline.FishTank.services::SpecialEventManager/onGetSettings()" }) : TypeError: Error #1010: A term is undefined and has no properties. (accessing field: events)
        at src.com.gaiaonline.FishTank.services::SpecialEventManager/onGetSettings()
        at flash.events::EventDispatcher/dispatchEventInternal()
        at flash.events::EventDispatcher/dispatchEvent()
        at src.com.gaiaonline.FishTank.services::DataConnector/onGSILoaded()
        at flash.events::EventDispatcher/dispatchEventInternal()
        at flash.events::EventDispatcher/dispatchEvent()
        at com.gaiaonline.gsi::GSIGateway/onComplete()
2025-02-14T22:19:50.642730Z ERROR ruffle_core::avm2::events: Error dispatching event EventObject { type: "getUserEnvironment", class: src.com.gaiaonline.FishTank.events::DataConnectorEvent, ptr: 0x2a5c77646f0 } to handler FunctionObject(FunctionObject { ptr: 0x2a5c5b76800, name: "FishTank/onUserEnvironment()" }) : TypeError: Error #1010: A term is undefined and has no properties. (accessing field: user_id)
        at FishTank/onUserEnvironment()
        at flash.events::EventDispatcher/dispatchEventInternal()
        at flash.events::EventDispatcher/dispatchEvent()
        at src.com.gaiaonline.FishTank.services::DataConnector/onGSILoaded()
        at flash.events::EventDispatcher/dispatchEventInternal()
        at flash.events::EventDispatcher/dispatchEvent()
        at com.gaiaonline.gsi::GSIGateway/onComplete()
2025-02-14T22:19:50.642782Z ERROR ruffle_core::avm2::events: Error dispatching event EventObject { type: "getUserEnvironment", class: src.com.gaiaonline.FishTank.events::DataConnectorEvent, ptr: 0x2a5c77646f0 } to handler FunctionObject(FunctionObject { ptr: 0x2a5c5b77900, name: "src.com.gaiaonline.FishTank.miniGames::GameManager/onUserEnvironment()" }) : TypeError: Error #1010: A term is undefined and has no properties. (accessing field: game_info)
        at src.com.gaiaonline.FishTank.miniGames::GameManager/onUserEnvironment()
        at flash.events::EventDispatcher/dispatchEventInternal()
        at flash.events::EventDispatcher/dispatchEvent()
        at src.com.gaiaonline.FishTank.services::DataConnector/onGSILoaded()
        at flash.events::EventDispatcher/dispatchEventInternal()
        at flash.events::EventDispatcher/dispatchEvent()
        at com.gaiaonline.gsi::GSIGateway/onComplete()

[kjarosh]

LGTM!