Kernel: namespace and function renames

MMU moved to namespace kernel
Kernel::Memory::Heap moved to just Kernel
MMU::map_{page,range} renamed to identity_map_{page,range}

Add MMU::get_page_flags

kernel/include/kernel/Memory/Heap.h

@@ -7,9 +7,10 @@
 
 #define PAGE_SIZE 4096
 
-namespace Kernel::Memory
+namespace Kernel
 {
 
+	using vaddr_t = uintptr_t;
 	using paddr_t = uintptr_t;
 
 	class PhysicalRange