Note

Adds LayoutReference abstraction and migrates pre_cancellation_tracker and bulk_order_book to use it, updating constructors, accessors, and destruction paths.

• Aptos Stdlib:
  • New aptos_framework::layout_reference: Introduces LayoutReference<T> (Inline | ExternalTable) with new_external_table, borrow, borrow_mut, destroy, and move helpers.
• Trading:
  • Market (market_types.move):
    • Replace Table<u8, PreCancellationTracker> with LayoutReference<PreCancellationTracker>.
    • Update new_market to layout_reference::new_external_table(...), get_pre_cancellation_tracker_mut to borrow_mut(), and cleanup via destroy().
  • Order Book (order_book.move):
    • Replace BulkOrderBook<M> with LayoutReference<BulkOrderBook<M>>.
    • Construct via layout_reference::new_external_table(...), access via borrow()/borrow_mut(), destroy via destroy().

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