Everywhere: Move global Kernel pattern code to Kernel/Library directory

This has KString, KBuffer, DoubleBuffer, KBufferBuilder, IOWindow,
UserOrKernelBuffer and ScopedCritical classes being moved to the
Kernel/Library subdirectory.

Also, move the panic and assertions handling code to that directory.

Kernel/Interrupts/GenericInterruptHandler.cpp

@@ -6,8 +6,8 @@
 
 #include <Kernel/Arch/InterruptManagement.h>
 #include <Kernel/Arch/Interrupts.h>
-#include <Kernel/Assertions.h>
 #include <Kernel/Interrupts/GenericInterruptHandler.h>
+#include <Kernel/Library/Assertions.h>
 
 namespace Kernel {
 GenericInterruptHandler& GenericInterruptHandler::from(u8 interrupt_number)

Kernel/Interrupts/SharedIRQHandler.cpp

@@ -5,10 +5,10 @@
  */
 
 #include <Kernel/Arch/InterruptManagement.h>
-#include <Kernel/Assertions.h>
 #include <Kernel/Debug.h>
 #include <Kernel/Interrupts/IRQHandler.h>
 #include <Kernel/Interrupts/SharedIRQHandler.h>
+#include <Kernel/Library/Assertions.h>
 #include <Kernel/Sections.h>
 
 namespace Kernel {

Kernel/Interrupts/UnhandledInterruptHandler.cpp

@@ -5,7 +5,7 @@
  */
 
 #include <Kernel/Interrupts/UnhandledInterruptHandler.h>
-#include <Kernel/Panic.h>
+#include <Kernel/Library/Panic.h>
 
 namespace Kernel {
 UnhandledInterruptHandler::UnhandledInterruptHandler(u8 interrupt_vector)