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/Memory/MemoryManager.cpp

@@ -15,15 +15,15 @@
 #include <Kernel/Heap/kmalloc.h>
 #include <Kernel/InterruptDisabler.h>
 #include <Kernel/KSyms.h>
+#include <Kernel/Library/Panic.h>
+#include <Kernel/Library/StdLib.h>
 #include <Kernel/Memory/AnonymousVMObject.h>
 #include <Kernel/Memory/MemoryManager.h>
 #include <Kernel/Memory/PhysicalRegion.h>
 #include <Kernel/Memory/SharedInodeVMObject.h>
 #include <Kernel/Multiboot.h>
-#include <Kernel/Panic.h>
 #include <Kernel/Prekernel/Prekernel.h>
 #include <Kernel/Sections.h>
-#include <Kernel/StdLib.h>
 #include <Kernel/Tasks/Process.h>
 
 extern u8 start_of_kernel_image[];