`time` precision is not respected

It seems like the `time` type is hardcoded to always be `time(6)`. We need to update the `time` type to respect the actual precision.

Dolt
```
tmp/main*> SELECT CAST('12:34:56.123456' AS TIME);
+---------------------------------+
| CAST('12:34:56.123456' AS TIME) |
+---------------------------------+
| 12:34:56.123456 |
+---------------------------------+
1 row in set (0.00 sec)

tmp/main*> select cast('12:34:56.123' as time(1));
+---------------------------------+
| cast('12:34:56.123' as time(1)) |
+---------------------------------+
| 12:34:56.123000 |
+---------------------------------+
1 row in set (0.00 sec)
```

MySQL
```
mysql> SELECT CAST('12:34:56.123456' AS TIME);
+---------------------------------+
| CAST('12:34:56.123456' AS TIME) |
+---------------------------------+
| 12:34:56 |
+---------------------------------+
1 row in set (0.00 sec)

mysql> select cast('12:34:56.123' as time(1));
+---------------------------------+
| cast('12:34:56.123' as time(1)) |
+---------------------------------+
| 12:34:56.1 |
+---------------------------------+
1 row in set (0.00 sec)
```

Reproduce the two CAST examples from the issue, then locate the time type and CAST handling in the SQL implementation. Compare the results with the documented MySQL behavior; done means TIME preserves default precision and applies the requested precision such as TIME(1).

Written by the indexing model from the issue text.