Add API deleted to the list of resource events

# What are you trying to achieve?

I would like to use APIC as the source of truth for APIs and when a new API is added/modified it syncs automatically with the API ecosystem. Currently the API deletion don't generate any event and that blocks this strategy.

# Proposed solution

Implement the API deletion event.

# Alternative solutions

The API updated event could be used and then the event handling logic would need to check if the API still exists in APIC.

# Additional context