Make lock_sys use page_id_t

The InnoDB buffer block page descriptor is caching a value buf_block_t::lock_hash_val that would be very quick to compute especially on 64-bit systems if the record locks used a single 64-bit page_id_t instead of handling two register-width parameters for tablespace identifier and page number.

Let us remove buf_block_t::lock_hash_val to improve the locality of reference and to reduce the memory footprint, and let us make the lock subsystem handle 64-bit page_id_t like many other subsystems do in the 10.5 release.