Add an internal ASSERT macro

This macro has some advantages over the standard library one:
 - It prints the place where the macro was triggered
 - It "references" the condition even in Release to avoid warnings
 - In release, if possible, it gives compiler hints

It is basically is stripped down version of the ASSERT macros I wrote
for the Daemon engine in src/common/Assert.h

This commit also removes the stray "backend" namespaces for common/
code.

src/utils/D3D12Binding.cpp

@@ -14,18 +14,17 @@
 
 #include "utils/BackendBinding.h"
 
+#include "common/Assert.h"
+
 #define GLFW_EXPOSE_NATIVE_WIN32
 #include "GLFW/glfw3.h"
 #include "GLFW/glfw3native.h"
 
-#include <cassert>
 #include <initializer_list>
 #include <wrl.h>
 #include <d3d12.h>
 #include <dxgi1_4.h>
 
-#define ASSERT assert
-
 using Microsoft::WRL::ComPtr;
 
 namespace backend {
@@ -229,7 +228,7 @@ namespace utils {
             ComPtr<ID3D12GraphicsCommandList> commandList;
 
             static void ASSERT_SUCCESS(HRESULT hr) {
-                assert(SUCCEEDED(hr));
+                ASSERT(SUCCEEDED(hr));
             }
 
             static bool GetHardwareAdapter(IDXGIFactory4* factory, IDXGIAdapter1** hardwareAdapter) {