`INTERVAL` literal with duplicated interval types should raise error

[waitingkuo]

Describe the bug
A clear and concise description of what the bug is.

To Reproduce
Steps to reproduce the behavior:

❯ select interval '1 second 1 second';
+------------------------------------------------+
| IntervalDayTime("2000")                        |
+------------------------------------------------+
| 0 years 0 mons 0 days 0 hours 0 mins 2.00 secs |
+------------------------------------------------+
1 row in set. Query took 0.000 seconds.

note that it's not allowed in postgrseql

willy=# select interval '1 second 1 second';
ERROR:  invalid input syntax for type interval: "1 second 1 second"
LINE 1: select interval '1 second 1 second';

Expected behavior
A clear and concise description of what you expected to happen.

Additional context
Add any other context about the problem here.