feat(client): introduce Socky 🧦 - the nifty internal socket state man…

…ager (#8)

* feat(client): add Socky 🧦 - the internal socket state manager

* fix(socky): the sink might complete before `prepare` has has finished

* test: disposing while subscribing

* refactor: simplify Socky and small comment changes

* refactor: set whole state in one swab

* refactor: unnecessary type

* refactor: simplification

* fix: "concurrent" safe and allow pending sinks to connect on next socket

* test: fix stack cleanup