Add Move to the Top button on Manage User Directories interface

[adriazalvarez]

Report to: Robert Dalgliesh

Is your feature request related to a problem? Please describe.

A user has reported through the Mantid help mail a cumbersome workflow when handling multiple search paths in the Data Search Directories list:
"There is a significant penalty in Mantid to having a very large number of search paths in the manage user directories in Mantid on IDAaaS. Given that mantid paths are autoconfigured on IDAaaS adding new folders is quite an irritating process.
Can the addition of a “Move to top” button be considered in addition to the “move up” and “move down” ones that exist on the interface"

Describe the solution you'd like

Adding a button on the Manager User Directories interface which sends the selected search directory to the top.

Describe alternatives you've considered

Additional context

[thomashampson]

Would it be preferable to allow the items to be draggable to change the order? Otherwise we might end up with too many buttons.

[adriazalvarez]

If there are a large number of search paths, as Robert seems to be using, dragging the item up may be cumbersome too. I would personally prefer a button.