Add Blender Controllers

Just like the [flyviews](https://github.com/Harium/propan/tree/master/src/main/java/com/harium/propan/core/view) but compatible with libgdx's camera.

Start by reading the flyviews implementation in src/main/java/com/harium/propan/core/view, then inspect how the GDX backend exposes its camera. The feature is complete when Blender-style controllers are available and compatible with the libgdx camera; no tests are mentioned in the issue.

Written by the indexing model from the issue text.