Functions with `DEFAULT nextval()` break autocomplete + function view

## What did you do?

- I created the following reduced test-case function with a parameter defaulted to `nextval`:
- ```sql
CREATE SEQUENCE IF NOT EXISTS test_seq;
CREATE OR REPLACE FUNCTION public.test(id integer DEFAULT nextval('test_seq'))
RETURNS boolean
RETURN false;
```
- Notably, changing out `nextval` for a different function call, ie `degrees(0.5)` seemed to remove the issue. I'm not sure exactly what part of the `nextval` call is breaking the parser, but it's clearly not the function call.
- I typed in the SQL editor
- I opened the function view from the sidebar entry `test (integer)`

## What did you expect to happen?

- I expected autocomplete to work
- I expected the function view to work

## What actually happened?

- Autocomplete failed and the following error popped up:


- The function viewer failed and the following error popped up:

## What software versions are you using?

**Postico version:** 2.1 (9682)
**macOS version:** Sonoma 14.3
**PostgreSQL version:** 16.1

Reproduce the issue in the SQL editor with the provided CREATE SEQUENCE and CREATE FUNCTION statements against PostgreSQL 16.1, then inspect the autocomplete and sidebar entry `test (integer)` function-view paths. Done means the `nextval` default no longer causes either view to fail and autocomplete works for the reproduced case.

Written by the indexing model from the issue text.