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/v6/v6.go

@@ -0,0 +1,29 @@
+package v6
+
+import (
+	"context"
+	"errors"
+
+	"github.com/buger/jsonparser"
+)
+
+// Version implements ConfigVersion
+type Version struct{}
+
+// UpgradeConfig checks and upgrades the portfolioAddresses.providers field
+func (*Version) UpgradeConfig(_ context.Context, e []byte) ([]byte, error) {
+	_, valueType, _, err := jsonparser.Get(e, "portfolioAddresses", "providers")
+	switch {
+	case errors.Is(err, jsonparser.KeyPathNotFoundError), valueType == jsonparser.Null:
+		return jsonparser.Set(e, DefaultConfig, "portfolioAddresses", "providers")
+	case err != nil:
+		return e, err
+	}
+	return e, nil
+}
+
+// DowngradeConfig removes the portfolioAddresses.providers field
+func (*Version) DowngradeConfig(_ context.Context, e []byte) ([]byte, error) {
+	e = jsonparser.Delete(e, "portfolioAddresses", "providers")
+	return e, nil
+}