R1:58e2fa0d47fd

Differentiate between "Move Tasks to Column..." and "Move Tasks to Project..." in the workboard UI

Summary:
Depends on D20635. Ref T4900. Fixes T13316.

Currently, "Move Tasks to Column..." first prompts you to select a project, then prompts you for a column. The first step is prefilled with the current project, so the common case (moving to another column on the same board) requires you to confirm that you aren't doing an off-project move by clicking "Continue", then you can select a column.

This isn't…