stream ID in delivery endpoints

[timcappalli]

On the 2022-06-14 call, @FragLegs brought up that the delivery endpoints need to have the stream ID either as a path component or query parameter.

We need to at least have a default pattern / parameter with a potential option to override via metadata.

SET Pull
For the pull transport (poll), the endpoint is defined by the transmitter.

SET Push
For the push transport (webhook), the endpoint is defined by the receiver.

[timcappalli]

2022-06-28 call: consensus to use a path for the stream ID /stream/:id

Open question: should GET /stream return an array of all configured streams? Leaning towards yes.

[timcappalli]

Open question: should GET /stream return an array of all configured streams? Leaning towards yes.

call 2023-03-21: this was already addressed in a previous change (GET /stream with no params will return an array)