* feat(rpc module): add_stream to subscription sink

* fix some nits

* unify parameters to rpc methods

* Update core/src/server/rpc_module.rs

* Update tests/tests/integration_tests.rs

Co-authored-by: David <[email protected]>

* address grumbles

* fix subscription tests

* new type for `SubscriptionCallback` and glue code

* remove unsed code

* remove todo

* add missing feature tokio/macros

* make `add_stream` cancel-safe

* rename add_stream and return status

* fix nits

* rename stream API -> streamify

* Update core/src/server/rpc_module.rs

* provide proper close reason

* spelling

* consume_and_streamify + docs

* fmt

* rename API pipe_from_stream

* improve logging; indicate which subscription method that failed

Co-authored-by: David <[email protected]>