[gameplay] [client] blackfrost anivia Q 2 bugs

Hello team,

I wanted to report 2 bugs, one concerning anivia Q for all skins, and another one specifically for blackfrost anivia (i haven't tested on other skins).

Bug 1: anivia's Q count as 1 spell when launching the missile, and another spell when detonating it. This affects tear's building and luden's echo spell count (as well as other spells like maokai passive or kassadin E). It should be only one spell, and not 2 separate.

Bug 2: on blackfrost anivia, at around one third of occurrence, when using Q the missile becomes invisible for the caster (anivia), I don't know if teammates or opponents see it or if it's also invisible. The missile can still be detonated and keeps all the usual spell mechanics (distance, speed, damage, slow, stun...).

I would even go as far as hoping one day that anivia ultimate would not be cancelled by every CC in the game, while swain, maokai and karthus can just keep them toggled even CCed. Considering that nearly all new champions have hard CC this would be no luxury.

Thanks.