Subscriptions and blocking next() #638
Description
Currently subscriptions are blocking in the sync case. See here:
substrate-api-client/src/rpc/jsonrpsee_client/subscription.rs
Lines 30 to 31 in 4d4f198
Check whether it is possible to "break" this blocking by calling
unsubscribe() and if yes also allow the user to use this to cancel calls to next() that are stuck.See this previous discussion: #635 (comment)