EXCLUDE constraint does not show properly

## What did you do?

I have created an EXCLUDE constraint:

```sql
ALTER TABLE event ADD CONSTRAINT unique_event_by_movie_id EXCLUDE (movie_id WITH =,venue_id WITH =,starts_at WITH =, (CASE WHEN unlisted_at IS NULL THEN 1 ELSE 0 END) WITH =) DEFERRABLE INITIALLY IMMEDIATE;
ALTER TABLE event ADD CONSTRAINT unique_event_by_cinema_movie_name_id EXCLUDE (cinema_movie_name_id WITH =,venue_id WITH =,starts_at WITH =, (CASE WHEN unlisted_at IS NULL THEN 1 ELSE 0 END) WITH =) DEFERRABLE INITIALLY IMMEDIATE;

```

## What did you expect to happen?

I expected to be able to edit the constraint in the table Structure view.

## What actually happened?

The exclude constraint is not being displayed properly and I cannot edit the constraint definition.

## What software versions are you using?

Version 1.4.1 (2841)

Reproduce the issue in the table Structure view using the supplied PostgreSQL EXCLUDE constraints, then trace how constraints are displayed and edited there. Done means EXCLUDE constraints appear correctly and their definitions can be edited without losing the expressions or options.

Written by the indexing model from the issue text.