Worker AI tweaks (#10954)

Workers will now consider tiles safe if there's a friendly military unit that's able to defend it.

Improvement planner AI will now:

 * try to put GP improvements where no other good improvements can be put,

 * take not yet unlocked improvements into account when planning improvements,

 * take chop production into account,

 * be better in general at planning GP improvements, no-two-adjacent improvements, and two-same-adjacent buffing improvements.

Should now be better at taking future city connections into account when planning improvements.

Slightly reduce value of food when evaluating improvements.

Don't plan improvements on antiquity sites.

Workers now less eager to build improvements far away.

(1) Community Patch/Core Files/Core Values/CoreDefines.sql

@@ -206,7 +206,7 @@ UPDATE Defines SET Value = 1000 WHERE Name = 'BUILDER_TASKING_BASELINE_REPAIR';
 UPDATE Defines SET Value = 750 WHERE Name = 'BUILDER_TASKING_BASELINE_BUILD_ROUTES';
 UPDATE Defines SET Value = 300 WHERE Name = 'BUILDER_TASKING_BASELINE_BUILD_RESOURCE_IMPROVEMENTS';
 UPDATE Defines SET Value = 100 WHERE Name = 'BUILDER_TASKING_BASELINE_BUILD_IMPROVEMENTS';
-INSERT INTO Defines (Name, Value) SELECT 'BUILDER_TASKING_BASELINE_ADDS_FOOD', 200;
+INSERT INTO Defines (Name, Value) SELECT 'BUILDER_TASKING_BASELINE_ADDS_FOOD', 180;
 INSERT INTO Defines (Name, Value) SELECT 'BUILDER_TASKING_BASELINE_ADDS_GOLD', 40;
 INSERT INTO Defines (Name, Value) SELECT 'BUILDER_TASKING_BASELINE_ADDS_FAITH', 150;
 INSERT INTO Defines (Name, Value) SELECT 'BUILDER_TASKING_BASELINE_ADDS_PRODUCTION', 200;