Improve Layout Menu

[AdventurousGui]

The menu for marking layout boxes to OCR presents user experience issues:

• When moving and resizing the browser window, the boxes are not redrawn in the appropriate coordinates.
• In Firefox, the box preview is absent when dragging over the picture, and the position of existing boxes cannot be adjusted.
• The list of boxes cannot be reordered, and their grouping by type can make it difficult to keep track of the same box or undo accidental changes.

With this PR:

• Boxes are drawn in the appropriate relative position to the page image when resizing the browser window.
• Firefox shows the box preview, but adjusting the corners of existing boxes is still unresponsive most of the time.
• Using a new library dnd-kit, boxes can be reordered, to adjust their ID numbers according to the list order. The IDs are independent from box types, and boxes retain the same ID when changing their type from "text"/"remove" to "image".

Unresolved problems:

• Boxes that are cloned to all pages cannot be easily removed and "ungrouping" them has no effect: they must be deleted one by one.