Some polygon calculations are incorrect, THX

[malegend]

Hi! Some polygon calculations are incorrect，here's an example:

var p1 = Polygon.New(new List<Region>(){
    new() {

        Points = new List<Point>(){
            new (590.2275M, 388.9665M),
            new (588.9713M, 357.5612M),
            new (580.9713M, 157.5612M),
            new (579.6613M, 124.8115M),
            new (546.9327M, 123.0519M),
            new (453.9327M, 118.0519M),
            new (450.0673M, 189.9481M),
            new (510.3387M, 193.1885M),
            new (515.7725M, 329.0335M),
            new (291.9352M, 368.6799M),
            new (90.71116M, 205.0679M),
            new (65.42641M, 197.0921M),
            new (33.66756M, 222.1702M),
            new (45.28884M, 260.9321M),
            new (259.2888M, 434.9321M),
            new (272.0648M, 445.3201M),
            new (288.2787M, 442.4482M),
            new (559.2787M, 394.4482M)
        }
    }
}, false);
var p2 = Polygon.New(new List<Region>(){
    new() {
        Points = new List<Point>(){
            new (65.4264M, 197.0921M),
            new (70.5736M, 268.9079M),
            new (656.5736M, 226.9079M),
            new (651.4264M, 155.0921M)
        }
    }
}, false);

var unified = SegmentSelector.Union(p1, p2);