Added inline query handler, updated CHANGELOG, added group name validator

src/validator/groupNameValidator.py

@@ -0,0 +1,16 @@
+import re
+
+from exception.invalidArgumentException import InvalidArgumentException
+
+
+class GroupNameValidator:
+
+    @staticmethod
+    def validate(group: str) -> None:
+        group = group.lower()
+
+        if len(group) > 0 and not re.match(r"^[A-Za-z]+$", group):
+            raise InvalidArgumentException(re.escape('Group name must contain only letters.'))
+
+        if len(group) > 20:
+            raise InvalidArgumentException(re.escape(f'Group name length can not be greater than 20.'))