remove const for link functions

Develop 8888

* field: update draw(uint16 step, ...

* field: change signature of group raise_event

* remove (card*)0

* revert: X can gain an effect from itself

* reject EFFECT_UNIQUE_CHECK in adjust_grant_effect

* fix warning C4267

* card: use const member function

* update field::check_extra_link

* update card::is_position

* Update operations.cpp

* move to left or right pzone

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Co-authored-by: jwyxym <jwyxym@126.com>

match the definition in card, effect

effect::code is not a bit field.