Change abstract back to normal class for JsonRPCExecuteResponse.cs; Cleanup unused classes

Author: taooceros

Flow.Launcher.Core/Plugin/JsonPRCModel.cs

@@ -19,7 +19,6 @@
 
 namespace Flow.Launcher.Core.Plugin
 {
-    public record JsonRPCRequestMessage(PluginMetadata PluginMetadata, IAsyncEnumerable<JsonRPCRequestModel> Requests);
     public record JsonRPCBase(int Id, JsonRPCErrorModel Error = default);
     public record JsonRPCErrorModel(int Code, string Message, string Data);
 

Flow.Launcher.Core/Plugin/JsonRPCV2Models/JsonRPCExecuteResponse.cs

@@ -1,4 +1,4 @@
 namespace Flow.Launcher.Core.Plugin.JsonRPCV2Models
 {
-    public abstract record JsonRPCExecuteResponse(bool Hide = true);
+    public record JsonRPCExecuteResponse(bool Hide = true);
 }