Forking older versions of a note

When we have sequence of versions of a note, we can view or remove older versions but we also need UI elements to fork older version into new note. Fork means that we have several entries in version storage (`.ark/versions`) with the same _parent_.

E.g.
```
3155416 -> 7705444
5839051 -> 8921986
3155416 -> 9763586
```

Here, notes with _id_ `7705444` and `9763586` have the same _parent_ with _id_ `3155416`.

A button is needed in versions list, which allows to edit a version into new note.

Start by tracing the versions list and its existing view/remove actions, then inspect how note versions are stored under `.ark/versions` and how editing creates a note. Done means the versions list offers a way to edit an older version into a new note while preserving the shared `_parent_` relationship described in the issue.

Written by the indexing model from the issue text.