use vector_math library instead of custom vector implementation.
remove Vector2_crossNumAndVectorToOut. It does nearly the same as Vector2_crossVectorAndNumToOut.
use vector_math's crossInto() method instead of Vector3_crossToOut
use vector_math's transformed() method instead of Matrix2_mulMatrixAndVectorToOut
change attribute type hints form num to double
use vector_math's transposed() ans transformed() instead of Matrix2_mulTransMatrixAndVectorToOut