feat(util): new extension IEnumerable.IntersectAll<T>

Author: sindrekjr

AdventOfCode/Solutions/Utilities.cs

@@ -129,5 +129,8 @@ public static void Deconstruct<T>(this IList<T> list, out T first, out T second,
         }
 
         public static (int, int) Add(this (int x, int y) a, (int x, int y) b) => (a.x + b.x, a.y + b.y);
+
+        public static IEnumerable<T> IntersectAll<T>(this IEnumerable<IEnumerable<T>> input)
+            => input.Aggregate(input.First(), (intersector, next) => intersector.Intersect(next));
     }
 }