Kernel: Make self-contained locking smart pointers their own classes

Until now, our kernel has reimplemented a number of AK classes to
provide automatic internal locking:

- RefPtr
- NonnullRefPtr
- WeakPtr
- Weakable

This patch renames the Kernel classes so that they can coexist with
the original AK classes:

- RefPtr => LockRefPtr
- NonnullRefPtr => NonnullLockRefPtr
- WeakPtr => LockWeakPtr
- Weakable => LockWeakable

The goal here is to eventually get rid of the Lock* classes in favor of
using external locking.

Kernel/Interrupts/IRQHandler.h

@@ -6,10 +6,10 @@
 
 #pragma once
 
-#include <AK/RefPtr.h>
 #include <AK/Types.h>
 #include <Kernel/Arch/IRQController.h>
 #include <Kernel/Interrupts/GenericInterruptHandler.h>
+#include <Kernel/Library/LockRefPtr.h>
 
 namespace Kernel {
 
@@ -40,7 +40,7 @@ protected:
 private:
     bool m_shared_with_others { false };
     bool m_enabled { false };
-    RefPtr<IRQController> m_responsible_irq_controller;
+    LockRefPtr<IRQController> m_responsible_irq_controller;
 };
 
 }