Hide Memory Collection types for internal usage only

dotnet/src/Plugins/Plugins.Memory/Collections/MinHeap.cs

@@ -11,7 +11,7 @@ namespace Microsoft.SemanticKernel.Plugins.Memory.Collections;
 /// Implements the classic 'heap' data structure. By default, the item with the lowest value is at the top of the heap.
 /// </summary>
 /// <typeparam name="T">Data type.</typeparam>
-public sealed class MinHeap<T> : IEnumerable<T> where T : IComparable<T>
+internal sealed class MinHeap<T> : IEnumerable<T> where T : IComparable<T>
 {
     private const int DefaultCapacity = 7;
     private const int MinCapacity = 0;

dotnet/src/Plugins/Plugins.Memory/Collections/ScoredValue.cs

@@ -9,7 +9,7 @@ namespace Microsoft.SemanticKernel.Plugins.Memory.Collections;
 /// Structure for storing data which can be scored.
 /// </summary>
 /// <typeparam name="T">Data type.</typeparam>
-public readonly struct ScoredValue<T> : IComparable<ScoredValue<T>>, IEquatable<ScoredValue<T>>
+internal readonly struct ScoredValue<T> : IComparable<ScoredValue<T>>, IEquatable<ScoredValue<T>>
 {
     /// <summary>
     /// Initializes a new instance of the <see cref="ScoredValue{T}"/> struct.

dotnet/src/Plugins/Plugins.Memory/Collections/TopNCollection.cs

@@ -10,7 +10,7 @@ namespace Microsoft.SemanticKernel.Plugins.Memory.Collections;
 /// Automatically flushes out any not in the top N.
 /// By default, items are not sorted by score until you call <see cref="TopNCollection{T}.SortByScore"/>.
 /// </summary>
-public class TopNCollection<T> : IEnumerable<ScoredValue<T>>
+internal sealed class TopNCollection<T> : IEnumerable<ScoredValue<T>>
 {
     private readonly MinHeap<ScoredValue<T>> _heap;
     private bool _sorted = false;