FTX: Add REST staking and basic subaccount functionality (#692)

* Add FTX staking, missing margin APIs and basic subaccount support

* Fix backtester tests and add optional subaccount support to exchange_wrapper_issues tool

* subAccount to subaccount

* Fix TyPo

* Expand test coverage

* Address nitterinos

* Fix typos

* Remove unusued error type

backtester/backtest/backtest.go

@@ -652,6 +652,9 @@ func loadLiveData(cfg *config.Config, base *gctexchange.Base) error {
 	if cfg.DataSettings.LiveData.API2FAOverride != "" {
 		base.API.Credentials.PEMKey = cfg.DataSettings.LiveData.API2FAOverride
 	}
+	if cfg.DataSettings.LiveData.APISubaccountOverride != "" {
+		base.API.Credentials.Subaccount = cfg.DataSettings.LiveData.APISubaccountOverride
+	}
 	validated := base.ValidateAPICredentials()
 	base.API.AuthenticatedSupport = validated
 	if !validated && cfg.DataSettings.LiveData.RealOrders {

backtester/backtest/backtest_test.go

@@ -228,11 +228,12 @@ func TestLoadData(t *testing.T) {
 	}
 	cfg.DataSettings.CSVData = nil
 	cfg.DataSettings.LiveData = &config.LiveData{
-		APIKeyOverride:      "test",
-		APISecretOverride:   "test",
-		APIClientIDOverride: "test",
-		API2FAOverride:      "test",
-		RealOrders:          true,
+		APIKeyOverride:        "test",
+		APISecretOverride:     "test",
+		APIClientIDOverride:   "test",
+		API2FAOverride:        "test",
+		APISubaccountOverride: "test",
+		RealOrders:            true,
 	}
 	_, err = bt.loadData(cfg, exch, cp, asset.Spot)
 	if err != nil {
@@ -305,10 +306,11 @@ func TestLoadLiveData(t *testing.T) {
 			AuthenticatedWebsocketSupport: false,
 			PEMKeySupport:                 false,
 			Credentials: struct {
-				Key      string
-				Secret   string
-				ClientID string
-				PEMKey   string
+				Key        string
+				Secret     string
+				ClientID   string
+				PEMKey     string
+				Subaccount string
 			}{},
 			CredentialsValidator: struct {
 				RequiresPEM                bool
@@ -344,6 +346,7 @@ func TestLoadLiveData(t *testing.T) {
 	cfg.DataSettings.LiveData.APISecretOverride = "1234"
 	cfg.DataSettings.LiveData.APIClientIDOverride = "1234"
 	cfg.DataSettings.LiveData.API2FAOverride = "1234"
+	cfg.DataSettings.LiveData.APISubaccountOverride = "1234"
 	err = loadLiveData(cfg, b)
 	if err != nil {
 		t.Error(err)