Refactor renderer and input handling; add OBJ loader and math utilities

- Updated renderer.h to replace Vec3 and Vec2 structs with Math namespace equivalents.
- Introduced Texture struct to manage texture properties.
- Modified Triangle struct to use Texture instead of GLuint for texture handling.
- Removed deprecated matrix functions and replaced them with Math namespace methods.
- Implemented InputManager class for better input handling, including key and mouse state tracking.
- Added ObjLoader class to load OBJ files and associated textures, with MTL file parsing.
- Created math utilities for fixed-point arithmetic and vector/matrix operations.
- Added time management class for frame timing and delta time calculations.

Engine/math/math.h

@@ -0,0 +1,3 @@
+#include <vec3.h>
+#include <vec2.h>
+#include <matrix4.h>