Make Collections (and the Links within) sortable

[sigfrid87]

Why/User Benefit/User Problem

I was Opera user before. There it was possible to sort the collections/folders in the homescreen (called "speed dials"). Also within the folders, the user could move the Links via drag-and-drop. At current version, the last created Collection is top and within each Collection the last saved Link is top. So, order is "last-created"-only.

What/Requirements

Make Collections and the Links within Drag-and-drop-able, so that the user could move/sort them.

Acceptance Criteria (how do I know when I’m done?)

Job is finished when Collections/Links are moveable.

┆Issue is synchronized with this Jira Task

[ColourGrey]

Since it's about the same functionality, please also make the tabs in the list of open tabs moveable: long pressing on a tab and than dragging it upwards or downwards should move it up or down in the list of open tabs.

[plwt]

User feedback:- https://support.mozilla.org/en-US/questions/1379503

[boek]

Moved to bugzilla: https://bugzilla.mozilla.org/show_bug.cgi?id=1812756

Change performed by the Move to Bugzilla add-on.