Extend ability summary feature to Order Hall

[ckaotik]

I would love to see this feature for the order hall. This is just a starting point, as there are some rough edges in the code.

• C_Garrison.GetAllEncounterThreats is a nicely sorted list, but the order differs from the formerly used id order. I therefore added the mechanicsorter for WoD garrisons.
• Above list includes the old 6.0 mechanics, which seems like a Blizzard bug to me. I therefore manually excluded them.
• Mechanics include 3 "Boss" threats, which are mapped to the "specialization" of the followers. These are - of course - separate from the normal abilities.
• I treated traits with minion companion bonuses as "racial" and traits granting flat out bonuses as "bonus". However, there are a lot more of these effects that are abilities instead of traits (see Wowhead)

[ckaotik]

I noticed that the API doesn't tell us about alternative counters. On a Shaman, "Minions" can be countered for example by "Chain Lightning" or "Lightning Shield". These abilities are not interchangable.
However the latter ability provides no counter information at all:
C_Garrison.GetFollowerAbilityCounterMechanicInfo(513) => nil
C_Garrison.GetFollowerAbilityInfo(513).counters => {}

I have no idea how to work around this :/