Replaced parent 'text' with 'hidden' in sonata_type_model_list

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #1994
| License       | MIT

@rande I am not sure what is the purpose of the option `parent`. Can be removed?