Real Fixes 230503

Version 230503
- (#17) Barracks' description does not mention anti-cav
- (#16) POLICY_SKYSCRAPERS uses ERA_FUTURE in the base game
- (#1) Ibn Khaldun is bugged, gives only half extra yields
- (tech fix) Missing Deal Item types

Version 230428
Gameplay fixes:
- Arrow Storm and Marauding correctly don't work on districts (#14, #15).
- Corrected yields of Great Works from Babylon DLC (#10).
- Complete support for CLASS_ALL_ERAS to GA/GG i.e. now Warrior Monk, Nihang and Vampire get bonuses from GGs.
- Missing techs and projects added to favored items when pursuing Science Victory (#12).
- Gaul's mines (technical, #9).
Descriptions' fixes:
- Chateau can be built on Floodplains (#13).
- Vatican's ability has 6 range (#4).
- After Action policy gives 50% (#7).

Version 230419
- Added UNITAI_BUILD tag to 4 units that were missing it (e.g. Naturalist).
- Removed unnecessary fix related to missing music. The music patch works now.

Version 23409
- Tokugawa's ability now properly works for districts in cities up to 6 tiles from the capital. Without a fix it works for all districts up to 6 tiles from the capital, no matter where the city is actually located.
- Hagia Sophia's ability gives charges to Missionaried and Apostles, as in the description. Without a fix it gives charges to virtually all units (e.g. engineeres), leading to some unexpected effects.
- Strategic Air Force now properly works for all air units and carriers, regardless of era. Without a fix it was not working for Modern and Atomic aircrafts.
- Jadwiga's ability text gets proper icons.

Version 230404
- Start Biases reviewed and simplified.
- Support for BBS (Better Balanced Starts).
- Commented out changes to number of Natural Wonders (these were not fixes, just tweaks).
- Removed Ramses change (was actually wrong).
- Added a fix for Barbarian Cavalry attack force on hihger diff (courtesy of Brixter).