Send events to GUI only before shutdown and in the proper order

[kozlovsky]

This PR does the following:

1. Fixes [7.13.0-RC1] RuntimeError: no running event loop #7353 by preventing events from being sent to the GUI when the EventsEndpoint is in the shutdown state and the event loop can already be closed.
2. Second, it adds a queue to ensure that all events are sent to GUI in the same order as they were created:

• Previously, a separate task was created for each event, which could lead to events being sent in reverse order, causing confusion on the GUI side.
• With this update, all events are sent through the same queue, preserving the order in which they were generated. The order of messages sent is determined by the order in which they were added to the queue.