accounts: account app qoshildi, tenant uchun sozlandi

core/utils/validators/phone_number.py

@@ -0,0 +1,7 @@
+# django
+from django.core.validators import RegexValidator
+
+uz_phone_validator = RegexValidator(
+    regex=r"^\+998\d{9}$",
+    message="The phone_number is invalid. The format should be like this: +998XXXXXXXXX"
+)