Add Event Bus Based Snowflake Event Notification Support (Fixes #40076)

This merge request adds an event bus for events in snowflake. In addition to this brief PT log outputs are added for the events. This event bus support none - many event consumers at the same time. Things to look at:

• The PT log output is very very brief. Not enough to diagnose the failure, but useful for providing feedback to users while the connection is in progress.
• The event bus supports dynamic add and removal of event listeners, but the performance isn't that great by design.
• The event bus does not check whether the event is a pointer or struct. This might create unexpected results during type assertion if not careful.