[STALE] Feat: add batched emergency spells

[amusingaxl]

I decided to remove the hard-coded ilks approach in favor of a more general one which allows us to specify the desired ilks in the constructor.

This approach requires some amount of hacking due to some Solidity limitations (i.e.: no support for immutable arrays, bytes32 <-> string conversion shenanigans).

While there is still some code duplication, this is significantly reduced compared to the previous approach.

Please notice that I renamed the original "multi"-ilk spells as "universal", while the term "multi" used for the new approach of passing a list in the constructor.

Due to the tight timelines here, it's best that we keep the existing naming conventions for the current contracts and simply have a different name for the new type. I'm dubbing them "Batched Emergency Spells" now.