API to add data to events

[NejcZdovc]

Create API where user can define additional data that will be sent with every event. User can define if this data will be sent out with regular events, dev events or both. This should be stored in local storage per type.

defaultEventData(type, data)
type: 'system', 'codified', 'pii', 'phi'
data: object

for reference: blotoutio/sdk-js#53