codebase: Cleanup various things (#1935)

* codebase: Rid base64/hex to string common funcs

* codebase: Rid local scope variable usage and other improvements

* codebase: Refactor currency pair usage across multiple exchanges

- Updated HitBTC tests to use the new currency pair format.
- Modified Kraken futures types to use currency.Pair instead of string for Symbol.
- Adjusted Kraken wrapper methods to handle currency pairs correctly.
- Refined OKX tests and types to utilize currency.Pair for instrument IDs.
- Enhanced Poloniex tests to consistently use predefined currency pairs.
- Streamlined order and orderbook tests to replace string pairs with currency.NewBTCUSD().
- Improved Yobit tests to utilize a standardized currency pair format.
- Updated validator wrapper to use currency pairs directly instead of string conversions.

* codebase: Use types.Number where possible

* refactor: update PayoutFee type to types.Number for consistency

* Refactor: Remove crypto functions to use standard library and other minor changes

- Removed custom crypto functions for SHA256, SHA512, and MD5 from the common/crypto package.
- Replaced usages of removed functions with standard library implementations in various files including:
  - cmd/websocket_client/main.go
  - engine/apiserver.go
  - exchanges/kraken/kraken.go
  - exchanges/lbank/lbank.go
  - exchanges/okx/okx_business_websocket.go
  - exchanges/kucoin/kucoin_websocket.go
  - gctscript/vm/vm.go
- Updated tests to reflect changes in the crypto functions.
- Renamed several functions for clarity, particularly in the context of order book updates across multiple exchanges.

* refactor: replace assert with require for consistency in test assertions

* refactor: Improve Binance futures candlestick test, standardise orderbook update function names and improve test parallelism

* refactor: Replace require.Len with require.Equal for better output in TestGetFuturesKlineData

exchanges/exchange_test.go

@@ -1457,34 +1457,25 @@ func TestSetGlobalPairsManager(t *testing.T) {
 	assert.ErrorIs(t, err, errConfigPairFormatRequiresDelimiter, "SetGlobalPairsManager should error correctly")
 }
 
-func Test_FormatExchangeKlineInterval(t *testing.T) {
-	testCases := []struct {
-		name     string
+func TestFormatExchangeKlineInterval(t *testing.T) {
+	t.Parallel()
+	b := Base{}
+	for _, tc := range []struct {
 		interval kline.Interval
 		output   string
 	}{
 		{
-			"OneMin",
 			kline.OneMin,
 			"60",
 		},
 		{
-			"OneDay",
 			kline.OneDay,
 			"86400",
 		},
-	}
-
-	b := Base{}
-	for x := range testCases {
-		test := testCases[x]
-
-		t.Run(test.name, func(t *testing.T) {
-			ret := b.FormatExchangeKlineInterval(test.interval)
-
-			if ret != test.output {
-				t.Fatalf("unexpected result return expected: %v received: %v", test.output, ret)
-			}
+	} {
+		t.Run(tc.interval.String(), func(t *testing.T) {
+			t.Parallel()
+			assert.Equal(t, tc.output, b.FormatExchangeKlineInterval(tc.interval))
 		})
 	}
 }
@@ -1647,13 +1638,6 @@ func TestKlineIntervalEnabled(t *testing.T) {
 	}
 }
 
-func TestFormatExchangeKlineInterval(t *testing.T) {
-	b := Base{}
-	if b.FormatExchangeKlineInterval(kline.EightHour) != "28800" {
-		t.Fatal("unexpected value")
-	}
-}
-
 func TestSetSaveTradeDataStatus(t *testing.T) {
 	b := Base{
 		Features: Features{
@@ -1765,24 +1749,13 @@ func TestFormatSymbol(t *testing.T) {
 		},
 	}
 	err := b.SetAssetPairStore(asset.Spot, spotStore)
-	if err != nil {
-		t.Error(err)
-	}
-	pair, err := currency.NewPairFromString("BTC-USD")
-	if err != nil {
-		t.Error(err)
-	}
-	sym, err := b.FormatSymbol(pair, asset.Spot)
-	if err != nil {
-		t.Error(err)
-	}
-	if sym != "BTCUSD" {
-		t.Error("formatting failed")
-	}
-	_, err = b.FormatSymbol(pair, asset.Futures)
-	if err == nil {
-		t.Error("expecting an error since asset pair format has not been set")
-	}
+	require.NoError(t, err, "SetAssetPairStore must not error")
+	p := currency.NewBTCUSD().Format(*spotStore.ConfigFormat)
+	sym, err := b.FormatSymbol(p, asset.Spot)
+	require.NoError(t, err, "FormatSymbol must not error")
+	assert.Equal(t, "BTCUSD", sym, "FormatSymbol should format the pair correctly")
+	_, err = b.FormatSymbol(p, asset.Futures)
+	assert.ErrorIs(t, err, asset.ErrNotSupported)
 }
 
 func TestSetAPIURL(t *testing.T) {