🐛[BUG]: Incorrect sdf calculation in Polygon geometry #140

import numpy as np
from modulus.geometry.primitives_2d import Polygon

geo = Polygon([(0, 0), (1, 1), (1, -1)]) # triangle
point1 = {'x': np.array([[-1]], 'y': np.array([[0]])} # The y coordinate is the same as one point of the triangle
point2 = {'x': np.array([[0]], 'y': np.array([[2]])} # The x coordinate is the same as one point of the triangle
point3 = {'x': np.array([[0.01]], 'y': np.array([[2]])} # The x or y coordinates do not coincide with any point in the triangle

print(sdf.geo(point1, params={}) # sdf should be negative, but it is positive
print(sdf.geo(point2, params={})
print(sdf.geo(point3, params={})

geo = Polygon([(0, 0), (1, 1), (1, 0), (1, -1)]) # add dummy point to make 2 points with y-coordinate equal to point1

print(sdf.geo(point1, params={}) # sign of sdf becomes negative
print(sdf.geo(point2, params={})
print(sdf.geo(point3, params={})