Remove Spell Classes from Magic Signs

[b3brodie]

Context: CDDA added a feature where the spell menu allows sorting by spell class, ex: Since many of the spell signs have unique spell classes, this massively clutters the menu with many individual tabs for each sign. Removing the classes fixes this.

I created a character with the removed classes and they still spawn with the correct spells when added via profession / chargen traits:

[chaosvolt]

The reason these spells have spell classes is because of a bug in @korggent's magic code: a spell NEEDS to have a spell class associated with it in character generation, or else you can select the spell's associated trait in character creation, unselect the trait, then still get the spell completely for free. You might notice that's why all spells that have a class associated with it are ones you can buy in chargen.

Test that, if you select then deselect a spell in chargen, does it still give you the spell for free? If so, then we'll have to choose between fucky UI or an exploit.

[chaosvolt]

Though...eh fuck it, that's a DDA problem if players can end up exploiting Korg's bad code.