Made validator singleton (as it doesn't have any instance-dependent features)

src/validation/validator.py

@@ -3,6 +3,12 @@ from numbers import Number
 from src.errors.argument_exception import argument_exception
 
 class validator:
+    # Singleton
+    def __new__(cls):
+        if not hasattr(cls, "instance"):
+            cls.instance = super(validator, cls).__new__(cls)
+        return cls.instance
+
     def check_type(self, value, exp_type):
         """
             Валидация аргумента по типу