Phases from Smartsheet get their default assignees

A phase that comes in from a Smartsheet connection now gets the people set under Default Assigned for that phase in Rules Engine > Phases, whenever its row in the sheet doesn't name anyone. When the row does name people, the phase gets exactly those people, as before.

This happens once per phase. Take everyone off a phase later and the next sync leaves it that way. Phases the sync brought in earlier with nobody on them, and nobody named in the sheet, pick up their defaults at the next sync.

When Assignees syncs both ways on the connection, the same sync also writes those names into the row's empty cell, so the sheet shows who is on the phase.