Implement ordered folder support in Web UI

Proposed solution

When a user select one or several items and the selection bar is displayed, it should present two more items:

• move Up
• move Down

When >1 items are selected, they should behave as a group and retain their relative position to each other, unless there are constraints one of them cannot move and they start to collapse to a joint group.

ie. group indexes (1,3,4,6) -> moves up -> group index (1,2,3,5)

No Drag and Drop in the scope for this (when DnD is added to Web UI would be a better time)

Mockup

Action icons should be the same as collection ordering.

Acceptance criteria
Given on a Ordered Folder, items (1, 3, 4, 5) are selected
When "Up" action is pressed
Then Items should be at orders (1, 2, 3, 4)

Given on a Ordered Folder, items (1, 2) are selected
When "Up" action is pressed
Then Items should maintain orders.

Given on a Ordered Folder with 5 items, items (1, 3, 4, 5) are selected
When "Down" action is pressed
Then Items should be at orders (2, 3, 4, 5)

Note: 1 index is top item.