[mage] Frost APL rework

[wingsco]

General

• Opener is back to Frostbolt --> Icy Veins + Flurry for all profiles because its neutral for SS and ever so slightly better for FF.
• Tidied up a few things and made expressions more consistent over the entire APL. Also removed some remaining TA edge cases (it's now icy_veins.remains > or < 9 everywhere) which very rarely could have caused unintended actions.
• Mirror images are cast again so ppl looking at the sample sequence opener dont forget they exist.
• Generalised Transmitter and Spy usage - all profiles that dont use spymasters nor play one of the boltspam rotations will now use transmitter 12s before icy veins and complete the task in the first moments of the cd. Decent gains in st and aoe up to +0.8% for most profiles with single-on-use transmitter, EXCEPT for a few spellslinger DC builds in aoe (its only a few builds, a small loss, nobody likes SS DC in M+ anyway, and fixing that would require a lot of conditions so eh maybe another day).

Frostfire Frost

• Major rework cleave_ff - for 2 targets gains are up to +3.9% against unfreezables and up to +5.5% against freezable targets for some profiles
• Major rework aoe_ff - aoe now also starts at 3+ targets for Frostfire. Gains range from up to +2.5% at 3 targets up to 1.8% against 8 unfreezable targets for some profiles. Gains are higher against freezables (ff is shattering cms with novas now). Was able to simplify a lot of conditions around CoC, orb and cms usage in the process.
• Rework st_ff - found some really nice simplifications for the boltspam rotation especially around flurry and ice lance usage. Standard ice lance rotation also got a less stressfull flurry line. Gains are barely out of margin compared to the default but i think simplicity is king here over hyperoptimized complexity.

Spellslinger Frost

• Added sim support for splintering ray to aoe_ss and added sensible talent restrictions around blizzard.