engine/exchanges: Add GetCurrencyTradeURL wrapper func/gRPC endpoint (#1521)

* beginning the concept

* expands testing and implementations

* test standardisation, expansion

* more

* finish remainder, add rpc func

* lint

* grammar? I barely know her!

* wow i forgot something wow wow wow wow

* rm SendPayload

* enFixio!

* improve binance long-dated support

* update test design, update wrapper funcs

* adds kraken futures, adds bybit support

* fixes SIMPLE bugs

* s is for sucks

* fixed option url x2

* fixed silly test

exchanges/request/request.go

@@ -38,6 +38,8 @@ var (
 	ErrRequestSystemIsNil = errors.New("request system is nil")
 	// ErrAuthRequestFailed is a wrapping error to denote that it's an auth request that failed
 	ErrAuthRequestFailed = errors.New("authenticated request failed")
+	// ErrBadStatus is a wrapping error to denote that the HTTP status code was unsuccessful
+	ErrBadStatus = errors.New("unsuccessful HTTP status code")
 
 	errRequestFunctionIsNil   = errors.New("request function is nil")
 	errRequestItemNil         = errors.New("request item is nil")
@@ -260,8 +262,9 @@ func (r *Requester) doRequest(ctx context.Context, endpoint EndpointLimit, newRe
 
 		if resp.StatusCode < http.StatusOK ||
 			resp.StatusCode > http.StatusNoContent {
-			return fmt.Errorf("%s unsuccessful HTTP status code: %d raw response: %s",
+			return fmt.Errorf("%s %w: %d raw response: %s",
 				r.name,
+				ErrBadStatus,
 				resp.StatusCode,
 				string(contents))
 		}