[Reference] Reorder and group hidden toctrees

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | 2.2+
| Fixed tickets | -

Reordered the hidden toctrees according to the visible TOCs so that the Prev/Next links will work correctly.
There's some merge work for 2.3 needed because of the new field types `currency`, `submit`, `reset`, `button` and the removed "field" type.