feat(feral): add finisher combo point highlight for Feral Druid

[lafonth]

• Recolor CP4+CP5 with FERAL_FINISHER_COMBO_POINTS override color for Feral (specID 103)
• Under Berserk or Incarnation, restrict highlight to CP5 only
• Detect Berserk/Incarnation via UNIT_SPELLCAST_SUCCEEDED on a dedicated frame (GetPlayerAuraBySpellID and COMBAT_LOG are blocked for secret cooldowns in Midnight 12.0)
• Exact timers: Berserk 15s, Incarnation 20s (fixed durations, no talent modifiers in 12.0)
• Color configurable via existing power color override system

[lafonth]

Normal rotation (4th and 5th slot alternate color):

Under Berzerk or Incarnation (only 5th alternated):

[lafonth]

Discussed with Maystine (Echo guild) about it and he suggested to have something to show extra combo point when feral is under berzerk or incarnation. I have try multiple things and since the extra combo points are buffs it's making it a bit hard to track it.
I have found a way to do it but it is a bit hacky. but it works well imo.
I hope Blizzard will rework this Overflowing power buff into "extra combo point" or at least white list it to make it trackable in future patch.

Will commit soon the changes I was doing and share screenshots

[lafonth]

After multiple unsuccesful attempts (learning the hard way =p), Overflowing power buff is secret tainted and no trackable in the addon. I am not sure what is the process to make requests about that.
The default solution is simply to use the cooldown manager and to set the buff in the "tracked buff" section.

One last thing I would like to do in this PR is conditionnaly set the color of the energy bar before and after 50 energy.
Or put a visual indication like a vertical bar at 50 energy because Ferocious bire cost 25 energy but can be over powered when used above 50 energy.