Spellcasting Refactor

[zeel01]

Refactors the entire spellcasting system per #182

[zeel01]

Currently working on re-writing the entire spellbook organization system, this will replace both calls in the organizeSpellbook method:

organizeSpellbooks(spells) {
    this.data.spellbook = this.sheet._prepareSpellbook(this.data, spells);
    this.data.innateSpellbook = new InnateSpellbookPrep(this.data.spellbook, this.sheet).prepare();
}

The InnateSpellbookPrep class will be dropped, and reliance on the system-level _prepareSepllbook method will be dropped.

Currently, if you open a sheet the new spellbook data structures will be logged to the console, but the displayed info on the sheet is still unchanged.

[zeel01]

I've started working on the new templates to handle the new spellcasting format, so far I just have really basic stuff in place so that something prints out using the new spellbook organization.

[zeel01]

Alright, I've got it to the point where spellcasting features show up again, and they have descriptions and spell lists that work. Pretty close to parity with old features.

I don't think resources are working correctly yet, and I still need to implement some of the new complicated sorting logic. But the basics are now working.