Error if the action returns an array (v2.0.5)

If I create an action that returns an object that has a field with an array, then I get "invalid input syntax for type ...". On version 1.3.3, this worked.
```
{
"errors": [
{
"extensions": {
"path": "$",
"code": "data-exception"
},
"message": "invalid input syntax for type integer: \"[6760980, 6759992, 6761453, 6760641, 6761474, 6761492, 6761195, 6761226]\""
}
]
}
```

No source file or test is named. Start by reproducing the action result with an object containing an integer array on v2.0.5, then compare it with v1.3.3 and trace how the action output reaches PostgreSQL. Done means array-valued fields no longer produce the reported invalid integer syntax error, with regression coverage for the case.

Written by the indexing model from the issue text.