fix: Omit elbow body when the line forms a straight line

- It lets other lines jump over the vertices of the body that used to exist.

src/utils/elbowLine.spec.ts

@@ -17,6 +17,17 @@ describe("getOptimalElbowBody", () => {
       ]);
     });
 
+    test("should return empty when they have y margin and the same x value", () => {
+      expect(
+        getOptimalElbowBody(
+          { x: 5, y: 10 },
+          { x: 5, y: 20 },
+          { x: 0, y: 0, width: 10, height: 10 },
+          { x: 0, y: 20, width: 10, height: 10 },
+        ),
+      ).toEqual([]);
+    });
+
     test("when they don't have y margin but have x margin", () => {
       expect(
         getOptimalElbowBody(

src/utils/elbowLine.ts

@@ -107,6 +107,8 @@ function getOptimalElbowBody_2_8(
   const [qt, qr, , ql] = [qBounds.y, qBounds.x + qBounds.width, qBounds.y + qBounds.height, qBounds.x];
 
   if (pb < qt) {
+    if (p.x === q.x) return [];
+
     const y = (qt + pb) / 2;
     return [
       { x: p.x, y },