[board] Clean up the formatting of BitBoards

Use debug_tuple in the fmt::Debug implementation.
Implement fmt::Binary, fmt::UpperHex, and fmt::LowerHex by delegating to u64's version.

board/src/bitboard/bitboard.rs

@@ -47,10 +47,32 @@ impl BitBoard {
     }
 }
 
+impl fmt::Binary for BitBoard {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        // Delegate to u64's implementation of Binary.
+        fmt::Binary::fmt(&self.0, f)
+    }
+}
+
+impl fmt::LowerHex for BitBoard {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        // Delegate to u64's implementation of LowerHex.
+        fmt::LowerHex::fmt(&self.0, f)
+    }
+}
+
+impl fmt::UpperHex for BitBoard {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        // Delegate to u64's implementation of UpperHex.
+        fmt::UpperHex::fmt(&self.0, f)
+    }
+}
+
 impl fmt::Debug for BitBoard {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
-        let bits = self.0;
-        write!(f, "BitBoard({bits:064b})")
+        f.debug_tuple("BitBoard")
+            .field(&format_args!("{:064b}", self.0))
+            .finish()
     }
 }