Spells/Druid Fix Balance, Feral, Guardian and Restoration Affinity talents

[kytulendu]

Changes proposed:

• Fix Balance Affinity, Feral Affinity and Guardian Affinity talents not given spells.
• Add script for Sunfire spell (Added by Balance Affinity talent).
• Rename Ysera's Gift script name. From spell_dru_ysera_gift to aura_dru_ysera_gift

Issues addressed:

https://bt.ashamane.com/view.php?id=220

Tests performed:

Test compile on Kubuntu 18.04. Tested in-game, work as intended with issue listed below. Additional testing needed.

Known issues and TODO list:

• [x] Moonkin Form (https://www.wowhead.com/spell=197625) that was added by Balance Affinity doesn't change the caster's model to a Boomkin.
• [ ] Multiple version of Affinity auras was applied when choose some of Affinity talent Need to do a check before apply aura or not?

[kytulendu]

I have finished this patch and it seems to work as intended but with minor issue. Although additional testing are needed as I don't trust my-self who wrote this and also test it :P

[Traesh]

Just tested ingame, seems good to me even with the minor issues, but that's something we can improve later :)

[frostfire11]

One issue I have and this is not related to the affinity talent I think but with the spell visual. It seems that moonfire and sunfire doesnt display at all when using afffinity talent or when in caster form but displays correctly on the target when cast when in the actual balance spec in moonkin form. I'm trying to fix this but a bit unsure on where to look