Change order of objects inside collections

After a user request, we want to make it possible to change the order of objects inside a collection. This could also be relevant for Stories in the future, when objects can be connected by annotations. For now it is important to be able to reorganize the objects inside a collection.
Therefore we created the following designs and functions:

- There is a button that says "Change order" above the objects in the sidebar
- When clicking the button the sidebar changes into another mode where the order can be changed

**Reoder mode:**
- The cards get numbers to display the objects current position
- On the right each cards gets a bar where the object can be moved "one position up", "one position down", "to the beginning" or "at the end" of the list
- After reordering the changes can be saved or discarded and then the "Reorder" mode is left again