Use Subscription Manager from `jsonrpc-pubsub`: The Sequel (#6254)

* Bump jsonrpc pubsub, core, http, and ws

Right now these are the packages which _need_ to be updated
so I can just the latest `jsonrpc-pubsub` code. Once a release
it cut upstream the rest of the dependencies should be updated
as well.

* Use jsonrpc-pubsub's SubscriptionManager

This places sc-rpc-api::Subscriptions

* Bump jsonrpc-core outside of sc-rpc-*

* Update client/rpc tests

Right now one of the `author` tests is failing, I
need to think a bit about how best to fix it.

* Remove Subscriptions manager

There's no need for this implementation since we're
using the one from `jsonrpc-pubsub` now

* Fix author RPC test

This test used to check for a numerial subscription ID,
whereas now it uses a string based ID which is the default
provided by `jsonrpc-pubsub`'s subscription manager.

* Remove unused NumericIdProvider

* Add missing bracket

Removed one too many with that last one, lol

* Bump `js...