sc2: Adding carrier wc upgrade -- repair drones

[MatthewMarinets]

Adding Carrier war council upgrade -- repair drones.

Progress on #152
Pairs with client PR #302

Known issues

• Carriers without the upgrade can still build the repair drones, and only deploy them if they deploy all their interceptors. Investigating Fixed by specifying the magazine abil on the use magazine effect
• Getting the upgrade while a carrier is building interceptors doesn't give healing drones until after interceptors are done building. I think this is how the Karax upgrade behaves, so I'd prefer to leave it.
  • If this is really desirable to change, I think it's better to look at how war3 mod does it for exhume corpses. Uses a CEffectCreateUnit and a CEffectLoadContainer. I think this is preferable to doing it with triggers

Without upgrade

With upgrade