exchanges/request: abstract and consolidate rate limiting code to request package (#1477)

* initial consolidation of rate limiting code to request package to reduce bespoke code implementation

* continued

* finish abstraction

* lint

* exchanges: fix tests

* linter: fix

* poloniex: fix auth rate limit not being set

* ratelimiter: convert from token to weight

* glorious: nits addressed with fire

* linter: rip

* change func name set -> get

* fix test

* derbit: impl

---------

Co-authored-by: Ryan O'Hara-Reid <ryan.oharareid@thrasher.io>

exchanges/exmo/exmo_wrapper.go

@@ -90,7 +90,7 @@ func (e *EXMO) SetDefaults() {
 
 	e.Requester, err = request.New(e.Name,
 		common.NewHTTPClientWithTimeout(exchange.DefaultHTTPTimeout),
-		request.WithLimiter(request.NewBasicRateLimit(exmoRateInterval, exmoRequestRate)))
+		request.WithLimiter(request.NewBasicRateLimit(exmoRateInterval, exmoRequestRate, 1)))
 	if err != nil {
 		log.Errorln(log.ExchangeSys, err)
 	}