[position] Plumb capture mask and push mask arguments through all move generators

These masks will help when generating moves that address checks.
Create BitBoard::EMPTY and BitBoard::FULL.

bitboard/src/bitboard.rs

@@ -18,6 +18,9 @@ macro_rules! moves_getter {
 }
 
 impl BitBoard {
+    pub const EMPTY: BitBoard = BitBoard(0);
+    pub const FULL: BitBoard = BitBoard(0xFFFFFFFFFFFFFFFF);
+
     pub const fn empty() -> BitBoard {
         BitBoard(0)
     }