Show withdraws, deposits and channel settlement in history

[manuelwedler]

Is your feature request related to a problem? Please describe.
It would be nice if we could show the channel withdraws and deposits in the history. Additionally the settled channels could be shown.

Describe the solution you'd like
The API does not return the past withdraws, deposits and settled channels yet. We would need to add a new endpoint or add it to an existing one. For #418 the easiest would be to have one endpoint with all events that would get displayed in the history.

Describe alternatives you've considered
An alternative would be to fetch the deposit and withdraw events via web3. But this seems redundant to me as the client already fetches the events. Besides it would be quite difficult to merge the withdraw and deposit data with the payment history when we eventually solved #418.