Trailing space after `@primaryKe <name>y` smart tag causes error when used with `|` to modify virtual constraint
### Summary

I have this view:

```sql
create or replace view labelt_public.images
with
  (
    security_barrier,
    security_invoker,
    check_option = 'cascaded'
  ) as
select
  id,
  data_uri
from
  labelt_private.images;

comment on view labelt_public.images is $$
  @name Image
  @primaryKey id | @behavior -constraint:resource:update -constraint:resource:delete
  @behavior insert update delete
$$;
```

However, this causes an error to be thrown:
```
error: '@primaryKey' smart tag on labelt_public.images referenced non-existent attribute 'id '; known attributes: id, data_uri
```

I can fix this by making removing the space before `|`:
```diff
 comment on view labelt_public.images is $$
   @name Image
-  @primaryKey id | @behavior -constraint:resource:update -constraint:resource:delete
+  @primaryKey id| @behavior -constraint:resource:update -constraint:resource:delete
   @behavior insert update delete
 $$;
```

### Additional context

postgraphile: `5.0.0-beta.26`

### Possible Solution

It seems the space between `@primaryKey <name>` and `|` is included in `<name>` ("[...] referenced non-existent attribute **'id '**; [...]"). I'm guessing there's a `.trim()` missing somewhere.
