Rotate ground-units as in the campaign miz

This implements a logic to rotate groups which are generated from templates like the origin (ground unit) which was placed by the campaign designer

game/point_with_heading.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import math
+
 from dcs import Point
 from game.utils import Heading
 
@@ -16,3 +18,12 @@ class PointWithHeading(Point):
         p.y = point.y
         p.heading = heading
         return p
+
+    def rotate(self, origin: Point, heading: Heading) -> None:
+        """Rotates the Point by a given angle clockwise around the origin"""
+        ox, oy = origin.x, origin.y
+        px, py = self.x, self.y
+        radians = heading.radians
+
+        self.x = ox + math.cos(radians) * (px - ox) - math.sin(radians) * (py - oy)
+        self.y = oy + math.sin(radians) * (px - ox) + math.cos(radians) * (py - oy)