This is done with the intention to add new {Get,Subscribe}ActorEvents in a
future release (i.e. soon!) with both decoded values (dag-json represented)
and simplified (no flags or codec). But because this comes with some
trade-offs wrt fidelity of information (e.g. likely needing to drop events with
badly encoded values, and not retaining original codec), we need to also have
a Raw form of these APIs for consumers that want to take on the burden of
consuming them as they are.
Use a fresh context to remove the temporary filter installed solely to
get the actor events. This should reduce chances of failure in a case
where the original context may be expired/cancelled.
Refactor removal into a `defer` statement for a more readable, concise
return statement.
Use BlockDelay as the window for receiving events on the SubscribeActorEvents
channel. We expect the user to have received the initial batch of historical
events (if any) in one block's time. For real-time events we expect them to
not fall behind by roughly one block's time.
