scripts using `unk` field names

[ab9rf]

the following scripts have references to unknown fields (fields whose names start with unk); these should be cleaned up so that we don't get random failures as bay12 canonicalization continues

• [x] add-thought.lua
• [x] adv-fix-sleepers.lua
• [x] bodyswap.lua
• [x] exportlegends.lua
• [x] full-heal.lua
• [ ] launch.lua
• [x] makeown.lua
• [ ] siren.lua
• [ ] workorder.lua
• [x] fix/drop-webs.lua
• [x] gui/unit-syndromes.lua
• [x] internal/caravan/movegoods.lua
• [x] internal/caravan/pedestal.lua
• [x] internal/gm-units/editor_colors.lua
• [ ] modtools/create-unit.lua