KThread based debug

This commit starts a big refactor to the original debugger PR by merryhime. The debugger now interfaces with KThreads instead of the ExecutionContext.

The corresponding KThread debug functions properly suspend/resume the thread and call the underlying debug related function in the ExecutionContext.

I also added debugging support to the AppleHV ExecutionContext.

src/Ryujinx.HLE/HOS/Kernel/Process/ProcessExecutionContext.cs

@@ -48,11 +48,6 @@ namespace Ryujinx.HLE.HOS.Kernel.Process
         {
         }
 
-        public DebugState GetDebugState()
-        {
-            return DebugState.Stopped;
-        }
-
         public void StopRunning()
         {
             Running = false;