…MP with precision (#57347)

### Release note
1. Support `UTC_TIMESTAMP` with precision
```text
mysql> SELECT UTC_TIMESTAMP(5), UTC_TIMESTAMP(5) + 1;
+---------------------------+----------------------+
| UTC_TIMESTAMP(5)          | UTC_TIMESTAMP(5) + 1 |
+---------------------------+----------------------+
| 2025-10-27 06:38:34.45620 |       20251027063835 |
+---------------------------+----------------------+

mysql> SELECT UTC_TIMESTAMP(7);
ERROR 1105 (HY000): errCode = 2, detailMessage = scale must be between 0 and 6
```

2. Support `UTC_DATE` and `UTC_TIME`
```text
mysql> SELECT UTC_TIME(), UTC_TIME() + 1, UTC_TIME(6), UTC_TIME(6) + 1;
------------+----------------+-----------------+-----------------+
| UTC_TIME() | UTC_TIME() + 1 | UTC_TIME(6)     | UTC_TIME(6) + 1 |
+------------+----------------+-----------------+-----------------+
| 06:39:01   |    23941000001 | 06:39:01.934119 |     23941934120 |
+------------+----------------+-----------------+-----------------+

mysql> SELECT UTC_TIME(7);
ERROR 1105 (HY000): errCode = 2, detailMessage = scale must be between 0 and 6

mysql> SELECT UTC_DATE();
+------------+
| UTC_DATE() |
+------------+
| 2025-10-27 |
+------------+
```