[board] Implement position::builders::MoveBuilder

This builder takes a Position and a Move, validates the move, and makes the move
in that position. Its build() method returns a new Position with the move made.

board/src/move.rs

@@ -10,6 +10,14 @@ use std::fmt;
 
 pub(crate) use move_formatter::AlgebraicMoveFormatter;
 
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub enum MakeMoveError {
+    PlayerOutOfTurn,
+    NoPiece,
+    NoCapturedPiece,
+    IllegalCastle,
+}
+
 #[repr(u16)]
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 pub enum Castle {