Improve math module (#396)

* Improve math module

- Mark almost everything constexpr
- Equality (a == b) is now exact, down to the bit level. If you want approximate equality use the new ApproxEqual method/static method
- Rename Nz::Extend to Nz::Extent
- Removed Make[] and Set[] methods in favor of their static counterpart and operator=

include/Nazara/Math/Enums.hpp

@@ -34,7 +34,7 @@ namespace Nz
 
 	constexpr std::size_t BoxCornerCount = UnderlyingCast(BoxCorner::Max) + 1;
 
-	enum class Extend
+	enum class Extent
 	{
 		Finite,
 		Infinite,