Describe the bug
When exporting annotation with Flashcard, the JSON line is undefined

    },
    undefined,
    {

To Reproduce
Steps to reproduce the behavior:

1. Annotate a line of text
2. Add a Flashcard with data on back and front
3. Export annotation as JSON
4. Search "undefined" you should get to that badly exported entry

Expected behavior

Fla

From Cascading and Inheritance:

If a shorthand is specified as one of the CSS-wide keywords, it sets all of its sub-properties to that keyword […].

It should be probably handled by the expander decorator.

Is your feature request related to a problem? Please describe.
I use xournalpp without the sidebar and recently spent a long time trying to figure out how, or if it was possible, to reorder pages. Looking through the wiki and web site and I could not find any mention but some issues here said "right click on the page and select move up" but right clicking on a page's blank area did nothing fo