Project structure refactor:

- Change package name general_server to gateway
- Changing the structure of directories and packages
- Adding vendor to the project

internal/core/utils/http_errors.go

@@ -0,0 +1,22 @@
+package utils
+
+import (
+	"encoding/json"
+	"net/http"
+)
+
+// writeJSONError writes a JSON error response to the HTTP response writer.
+// It sets the Content-Type to application/json, writes the specified HTTP status code
+func WriteJSONError(w http.ResponseWriter, status int, msg string) error {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	resp := map[string]any{
+		"status": "error",
+		"error":  msg,
+		"code":   status,
+	}
+	if err := json.NewEncoder(w).Encode(resp); err != nil {
+		return err
+	}
+	return nil
+}