Persistent subscription cannot start from the beginning of a stream

[alexeyzimarev]

We know the N+1 thing for subscriptions, so when creating a catch-up subscription, we should use the overload, which doesn't have the stream positions, to subscribe to the beginning of the stream.

However, persistent subscriptions express different behaviour, which is also inconsistent with other clients (NodeJS, Rust), so when I subscribe without giving it a position, it will use Stream.End. Although I understand the intention to make persistent subscriptions behaving in message broker style, it is confusing.

The biggest issue for me is that it seems literally impossible to create a persistent subscription for an existing stream and get the very first event. When given Stream.Start, it will subscribe from 0+1, the second event.

[ylorph]

Solved with
#188