Config: Refactor version packages (#1887)

* Config: Move config versions to separate pacakges

* Config: Move version tests to blackbox texts

* Config: Protect registerVersion from overflow

* Config: Protect against version already registered

config/versions/v1/v1.go

@@ -0,0 +1,53 @@
+package v1
+
+import (
+	"context"
+
+	"github.com/buger/jsonparser"
+	v0 "github.com/thrasher-corp/gocryptotrader/config/versions/v0"
+	"github.com/thrasher-corp/gocryptotrader/encoding/json"
+)
+
+// Version is an ExchangeVersion to upgrade currency pair format for exchanges
+type Version struct{}
+
+// Exchanges returns all exchanges: "*"
+func (*Version) Exchanges() []string { return []string{"*"} }
+
+// UpgradeExchange will upgrade currency pair format
+func (*Version) UpgradeExchange(_ context.Context, e []byte) ([]byte, error) {
+	if _, d, _, err := jsonparser.Get(e, "currencyPairs"); err == nil && d == jsonparser.Object {
+		return e, nil
+	}
+
+	d := &v0.Exchange{}
+	if err := json.Unmarshal(e, d); err != nil {
+		return e, err
+	}
+
+	p := &PairsManager{
+		UseGlobalFormat: true,
+		LastUpdated:     d.PairsLastUpdated,
+		ConfigFormat:    d.ConfigCurrencyPairFormat,
+		RequestFormat:   d.RequestCurrencyPairFormat,
+		Pairs: FullStore{
+			"spot": {
+				Available: d.AvailablePairs,
+				Enabled:   d.EnabledPairs,
+			},
+		},
+	}
+	j, err := json.Marshal(p)
+	if err != nil {
+		return e, err
+	}
+	for _, f := range []string{"pairsLastUpdated", "configCurrencyPairFormat", "requestCurrencyPairFormat", "assetTypes", "availablePairs", "enabledPairs"} {
+		e = jsonparser.Delete(e, f)
+	}
+	return jsonparser.Set(e, j, "currencyPairs")
+}
+
+// DowngradeExchange doesn't do anything for v1; There's no downgrade path since the original state is lossy and v1 was before versioning
+func (*Version) DowngradeExchange(_ context.Context, e []byte) ([]byte, error) {
+	return e, nil
+}