[GAMEPLAY] Trundle's Chomp both Triggers and Penetrates Spell Shields

The only part of Trundle's Chomp that is blocked by a spell shield is the AD drain. The bonus damage, slow, and AD boost all take effect rather than just the AD boost (since spell shields don't block an offensive spell's defensive components). It's obvious that the reason this occurs is that it's coded as an on-hit effect, but if that's the case, it should have no interaction whatsoever with spell shields. Please either make the entire spell an on-hit effect or make it a separate effect applied on the attack (so the slow and/or bonus damage are blocked as well). It's much better to lose 10-20 AD for 8 seconds than have a spell shield completely negated by an on-hit effect's least threatening component.

To reproduce the bug:

1. Enter a game with Sivir on one team and Trundle on the other.
2. Have Sivir start Spell Shield, and Trundle start Chomp.
3. Have Trundle Chomp Sivir while Spell Shield is active.

This also applies to other champions with mixed on-hit and spell effect abilities (to varying degrees of logic), but Trundle is the only champion able to penetrate a spell shield with a spell's crowd control component.