Move commonly used API systems to a plugin based system

Create a class that implements IBloodMagicPlugin and annotate it with
`@BloodMagicPlugin`. The `register` method will be called during init.

Currently implemented systems:
- Blacklisting
  - Teleposer
  - Teleposer (entity)
  - Transposition
  - Well of Suffering
  - Green Grove
- Setting sacrificial values
- Adding altar components

src/main/java/WayofTime/bloodmagic/block/BlockBloodLight.java

@@ -17,7 +17,7 @@ import net.minecraft.world.IBlockAccess;
 import net.minecraft.world.World;
 import net.minecraftforge.fml.relauncher.Side;
 import net.minecraftforge.fml.relauncher.SideOnly;
-import WayofTime.bloodmagic.registry.RegistrarBloodMagicItems;
+import WayofTime.bloodmagic.core.RegistrarBloodMagicItems;
 
 import javax.annotation.Nullable;