Adds tiered Antimagic, also makes Heretic school its own thing

[MrMelbert]

Antimagic is now tiered, split between "Weak", "Strong", and "Immune"

Items now provide differing strength of antimagic. Some items are better at warding magic than others.

Holymelons, for example, provide "Immune" to Holy Magic, but only "Weak" to generic magic.
This means they will either not be sufficiently strong enough to block certain spells (providing nothing at all), or will only partially block the effect (resulting in a lessened total effect).

Bibles only provide "Weak" holy resistance, which is strong enough to block Revenants, but not strong enough to block Cult magic. Which means it maintains status quo.

The Chaplain's Nullrod retains full immunity to "holy" and "generic" magic.

Disclaimer:

I didn't think too hard about the values I assigned, it was almost completely vibes based. Some stuff might be stupid.
It'd be appreciated if someone else took a closer look at what blocks what (and also, if someone added partial effects to more spells).

Other:

• I made heretic spells its own spell school rather than copying forbidden. And then I made them blocked by high tier holy resistance as well as generic resistance.
• Cult spells are blocked by high tier holy resistance as well.
• Holy and mind "magic block" effect will occur more commonly now. I changed the logic on how it determines which is played.