Add new Square descriptor and method for transforming targets relative to player perspective

[AnoubuzThuf]

Added:

• GeometricTargetDescriptor for descriptors which have different behaviour depending on the other descriptors used in the current SubSpell. Intended for Geometric shapes (Square, Circle...) with increasing radius depending on the number of repetitions.
• Add Square Descriptor implementing GeometricTargetDescriptor
• Add Circle Descriptor implementing GeometricTargetDescriptor
• Add MathHelper function for transforming targets relative to player perspective - this is really cool!

TODO is:

• Adding examples of these as spellbooks

Note:

• I've only tested this on NeoForge