Decided on Abstract Base class vs Interface

[ChuckJonas]

For decoupling the handler, there are two options:

1: Abstract Base Class with TriggerContext as injected variable (current implemenation)
2: Interface with void handle(TriggerContext ctx)

Although it strays from our current approach, I actually the interface has the advantage.

[ChuckJonas]

It does complicate backwards compatibility a bit though... We can create a base class that implements the existing Interface and everything just works. Having two competing interfaces is a bit of a mess...