Reordering descriptors in descriptor list

When editing a descriptor list the user must be have the possibility to reorder descriptors.

Add a "Reorder descriptors" action button to the edit page that:

1. Displays a list of only descriptor titles as <ListItem with "reorder" material-icon
2. Allows user to begin reorder operation by dragging the reorder icon up-down
3. Has "Save order" and "Cancel" buttons