This commit refactors the Camera class to add clarity and better logic:
- Integrates variables directly from constructor to the header for cleaner code
- Adds getters and setters for fov, speed, cameraSensitivity and position
- Duplicates projection matrix from cube to camera
- Adds comments to the header file
- TODO: the projection matrix from the cube loop function must now be replaced by the call to the `glm::mat4 getProjectionMatrix()` camera function
