[board] Update all the move generator submodules to use MoveBuilder instead of Move

Along the way update "manual" piece creation to use the macros instead.

board/src/position/position.rs

@@ -155,8 +155,8 @@ impl Position {
         Ok(())
     }
 
-    pub fn move_generator(&self, color: Color) -> Moves {
-        Moves::new(self, color)
+    pub fn moves(&self) -> Moves {
+        Moves::new(self, self.color_to_move)
     }
 
     /// Return a BitBoard representing the set of squares containing a piece.