A simple event trigger for Model Events that allows additional
data manipulation within the model. Specifically intended for
usage by child models this can be used to format data,
save/load related classes, etc.

It is the responsibility of the callback methods to return
the data itself.

Each $data array MUST have a 'data' key with the relevant
data for callback methods (like an array of key/value pairs to insert
or update, an array of results, etc)

@param string $event
@param array  $data

@return mixed
@throws \CodeIgniter\Database\Exceptions\DataException