Move non-output to new CppUtils namespace

We prefer to have the Outputs directory contain just one file or
namespace per output module, so we'll move all C++-related stuff to a
new CppUtils namespace instead.

Il2CppInspector.Common/Il2CppInspector.csproj

@@ -10,11 +10,11 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <None Remove="Outputs\UnityHeaders\**" />
+    <None Remove="CppUtils\UnityHeaders\**" />
   </ItemGroup>
 
   <ItemGroup>
-    <EmbeddedResource Include="Outputs\UnityHeaders\**" />
+    <EmbeddedResource Include="CppUtils\UnityHeaders\**" />
   </ItemGroup>
 
   <ItemGroup>