websocket/gateio: Support multi connection management and integrate with GateIO (#1580)

* gateio: Add multi asset websocket support WIP.

* meow

* Add tests and shenanigans

* integrate flushing and for enabling/disabling pairs from rpc shenanigans

* some changes

* linter: fixes strikes again.

* Change name ConnectionAssociation -> ConnectionCandidate for better clarity on purpose. Change connections map to point to candidate to track subscriptions for future dynamic connections holder and drop struct ConnectionDetails.

* Add subscription tests (state functional)

* glorious:nits + proxy handling

* Spelling

* linter: fixerino

* instead of nil, dont do nil.

* clean up nils

* cya nils

* don't need to set URL or check if its running

* stop ping handler routine leak

* * Fix bug where reader routine on error that is not a disconnection error but websocket frame error or anything really makes the reader routine return and then connection never cycles and the buffer gets filled.
* Handle reconnection via an errors.Is check which is simpler and in that scope allow for quick disconnect reconnect without waiting for connection cycle.
* Dial now uses code from DialContext but just calls context.Background()
* Don't allow reader to return on parse binary response error. Just output error and return a non nil response

* Allow rollback on connect on any error across all connections

* fix shadow jutsu

* glorious/gk: nitters - adds in ws mock server

* linter: fix

* fix deadlock on connection as the previous channel had no reader and would hang connection reader for eternity.

* gk: nits

* Leak issue and edge case

* gk: nits

* gk: drain brain

* glorious: nits

* Update exchanges/stream/websocket.go

Co-authored-by: Scott <gloriousCode@users.noreply.github.com>

* glorious: nits

* add tests

* linter: fix

* After merge

* Add error connection info

* Fix edge case where it does not reconnect made by an already closed connection

* stream coverage

* glorious: nits

* glorious: nits removed asset error handling in stream package

* linter: fix

* rm block

* Add basic readme

* fix asset enabled flush cycle for multi connection

* spella: fix

* linter: fix

* Add glorious suggestions, fix some race thing

* reinstate name before any routine gets spawned

* stop on error in mock tests

* glorious: nits

* glorious: nits found in CI build

* Add test for drain, bumped wait times as there seems to be something happening on macos CI builds, used context.WithTimeout because its instant.

* mutex across shutdown and connect for protection

* lint: fix

* test time withoffset, reinstate stop

* fix whoops

* const trafficCheckInterval; rm testmain

* y

* fix lint

* bump time check window

* stream: fix intermittant test failures while testing routines and remove code that is not needed.

* spells

* cant do what I did

* protect race due to routine.

* update testURL

* use mock websocket connection instead of test URL's

* linter: fix

* remove url because its throwing errors on CI builds

* connections drop all the time, don't need to worry about not being able to echo back ws data as it can be easily reviewed _test file side.

* remove another superfluous url thats not really set up for this

* spawn overwatch routine when there is no errors, inline checker instead of waiting for a time period, add sleep inline with echo handler as this is really quick and wanted to ensure that latency is handing correctly

* linter: fixerino uperino

* glorious: panix

* linter: things

* whoops

* defer lock and use functions that don't require locking in SetProxyAddress

* lint: fix

* thrasher: nits

---------

Co-authored-by: shazbert <ryan.oharareid@thrasher.io>
Co-authored-by: Scott <gloriousCode@users.noreply.github.com>

engine/rpcserver.go

@@ -2935,6 +2935,13 @@ func (s *RPCServer) SetExchangeAsset(_ context.Context, r *gctrpc.SetExchangeAss
 		return nil, err
 	}
 
+	if base.IsWebsocketEnabled() && base.Websocket.IsConnected() {
+		err = exch.FlushWebsocketChannels()
+		if err != nil {
+			return nil, err
+		}
+	}
+
 	return &gctrpc.GenericResponse{Status: MsgStatusSuccess}, nil
 }