Inconsistent SQL function types

Our SQL statements seem to have inconsitent types. The ones with `RETURNING` clause are:

With `:returning-execute`

```sql
-- :name add-application-event! :returning-execute :1
```

With plain `:insert`

```sql
-- :name create-application! :insert
-- :name put-to-outbox! :insert
-- :name add-organization! :insert
-- :name add-invitation! :insert
```

Is there a problem here?
See https://www.hugsql.org/using-hugsql/insert#option-1-insert--returning

Looks like if you intend to return more than just the generater id, you need to use the former.

Let's refactor so that we use only the latter `:insert` since it reads a bit better, and returning many values is basically extra.

- [ ] replace cases with `:returning-execute` with `:insert` and rewrite the code to not access the body result (`fix-event-from-db`)