[mobile] Repack page

[agritheory]

This page is intended to work as an abbreviated interface for a Repack sequence.
The page has five primary interfaces:

Item to Repack - Link
Qty
BOM (Optional) - Link
Source Warehouse - Link
Target Warehouse - Link
Items list -ListView

For the Items list, it can start empty but be populated by scanning or by populating the BOM field.

For the Source Warehouse and Target Warehouse, these should normally be populated by scanning but need to fallback to a link component. When a warehouse is scanned it should populate whichever of the fields is not already populated, with the source first if they are both empty. In the normal Frappe/ERPNext context a link has a "follow" icon on the right but in the mobile context this isn't useful and should be replaced with a "clear" button, denoted by the multiplication character.