Add tower abilities to combat log

[Kvel2D]

Call CombatLog.log_ability() in tower scripts.

This is already done for some towers. Should be done for all towers, where it's appropriate. Do not log very frequent abilities, for example abilities which are used on every attack should not be logged.

• [x] Common
• [x] Uncommon
• [x] Rare
• [x] Unique