Render bundles implementation

[martinlaxenaire]

• Added a BufferBindingOffsetChild class to create a buffer binding child using another buffer binding parent GPU buffer with an offset (allows to handle multiple transformations buffers into a single large buffer).
• Added a RenderBundle class. This class can create a parent binding buffer, therefore introducing major performances optimizations (up to +150% CPU perf gain in some edge cases).
• Updated the Scene and GPURenderer classes to handle the new RenderBundle class.
• Fixed the Light classes not working when passing a GPUCurtains instance to the constructor.
• Updated tests, examples and website.