Fixed Ranged and Siege promotions

There are some Ranged and Siege promotions that don't behave as expected.

Features:

1. Garrison (Ranged)

- Before: Attack and Defend
- After: Attack only

- This removes a ridiculous scenario. Currently, an Archer with Garrison promotion defending in an open tile gets +10 CS when attacked by a Warrior from inside a district.

2. Arrow Storm (Ranged)

- Before: Attacking Land and Naval units and districts
- After: Attacking Land and Naval units

- Arrow Storm is not intended for districts. That's what Incendiaries is for. Ranged units aren't supposed to be very good against districts. Siege units take care of that.

3. Emplacement (Ranged)

- Before: Defends against City Center only
- After: Defends against all districts including Encampment and Oppidum

- It makes no sense that it defends against City Center only when there are other districts that have ranged attacks.

4. Advance Rangefinding (Siege)

- Before: Attack only
- After: Attack and Defend

- For consistency, applied it to defense as well because the other Siege promotions, Grape Shot, Shrapnel and Shells, are Attack and Defend.