more type stubs

src/tg/detail/functions/normal.hh

src/tg/types/objects/ball.hh

src/tg/types/objects/circle.hh

src/tg/types/objects/disk.hh

src/tg/types/objects/objects.hh

src/tg/types/objects/sphere.hh

src/tg/types/pos.hh

src/tg/types/size.hh

src/tg/types/vec.hh