Implement Index<T>, IndexMut<T> for Castle, PieceType and Color enums, use swap_remove instead of remove on sort_moves

src/search/move_ordering.rs

@@ -5,7 +5,7 @@ use crate::{
 pub fn sort_moves(mut moves: Vec<Move>, mailbox: &Mailbox, tt_move: Option<Move>) -> Vec<Move> {
     if let Some(tt_move) = tt_move {
         if let Some(tt_move_index) = moves.iter().position(|&mv| mv == tt_move) {
-            moves.remove(tt_move_index);
+            moves.swap_remove(tt_move_index);
             moves.insert(0, tt_move);
             return moves;
         }