Update child emulator to work with new event structure

[cortadocodes]

Bug report

What is the current behavior?

The child emulator only works with a list of events and not the events' attributes. The ChildEmulator class also duplicates and modifies some of the event handling code, making its emulation less useful and the code harder to maintain

What is the expected behavior?

For emulation to be faithful, we need to include event attributes and run as much of the same code as a real child as possible.

Proposed Solution

Refactor ChildEmulator to inherit from the new AbstractEventHandler.