[QoL]{Decor} - fossil excavation.

[RadoslawP]

if we get the story trait we can get 4 big fossils to excavate,
sadly we cant move them, and I think it should be movable.
since it gives decor i should be able to move it into my base.
since each of it is 4 tiles in size, I think as a comprimise dupe should move at 50% speed.
in addition this object should not be droppable but placable.
Meaning if a drupe needs to "drop" it due say emergency alert - he cant, he must find closest place and place it there then move to other task.