Face down changes:
* GUI: added visible face down type and real card name for controller/owner (opponent can see it after game ends);
* GUI: added day/night button to view real card for controller/owner (opponent can see it after game ends);
* game: fixed that faced-down card can render symbols, abilities and other hidden data from a real card;
* images: added image support for normal faced-down cards;
* images: added image support for morph and megamorph faced-down cards;
* images: added image support for foretell faced-down cards;
Other changes:
* images: fixed missing tokens from DDD set;
* images: no more client restart to apply newly downloaded images or render settings;
* images: improved backface image quality (use main menu -> symbols to download it);
* server: added limit to max chat message (related to #11285);
* gui: fixed possible error after auto-submit deck;
* gui: fixed possible error after end game dialog;
* refactor: other code improves;
* server: fixed that a critical errors ignored in user commands threads (now it will be added to the logs);
* network: fixed frozen user responses in some use cases;
* network: fixed accidental and incorrect user responses (only latest response will be used now);
* network: improved freeze logs, added problem method name and code's line number;
* cheats: removed outdated deck and card load logic (only init.txt commands supports now);
* cheats: fixed wrong priority after add card dialog (closes#11437);
* cheats: improved stability and random errors on cheat executes (related to #11437);
* docs: added details on network and thread logic, human feedback life cycle, etc (see HumanPlayer, ThreadExecutorImpl);
