Fix BridgeDelegate lifecycle issues

[jayohms]

This addresses three lifecycle bugs that were overlooked:

• When the destination's onStop() was called, the onStop() event was not passed to the destination's components, because the destinationIsActive flag was set to false before attempting to pass along the onStop() event to active components
• The destinationIsActive flag defaulted to true instead of inspecting the destination's state directly
• Bridge messages received in bridgeDidReceiveMessage() did not check to see if the destination was active before passing along the message to the corresponding component. This meant that if a message was received from the web after the view had been destroyed, it would lead to a crash in the component if it attempted to access its view.

[mbarta]

Nice work 💪