basic summaries for all pair classes, create partial classes and condense models into a single file

LightlessSync/PlayerData/Pairs/PairHandlerAdapter.cs

@@ -28,6 +28,9 @@ using ObjectKind = LightlessSync.API.Data.Enum.ObjectKind;
 
 namespace LightlessSync.PlayerData.Pairs;
 
+/// <summary>
+///     orchestrates the lifecycle of a paired character
+/// </summary>
 public interface IPairHandlerAdapter : IDisposable, IPairPerformanceSubject
 {
     string Ident { get; }