"trim": does not work correctly on Postgresql

Drill 1.21.1
Postgresql 14.6

DrillBit storage configuration:
```javascript
{
"type": "jdbc",
"driver": "org.postgresql.Driver",
"url": "jdbc:postgresql:///",
"username": "",
"password": "",
"authMode": "SHARED_USER",
"writerBatchSize": 10000,
"enabled": true
}
```
Run this query
`SELECT TRIM( ' ') AS x FROM path_to_any_table`
Asume that the table has only one row.
The actual result:
x
--
null

The expected result
x
--

x should be an empty string.
The issue doesn't happen in Drill 1.19.0