Code new `Renderer` ADT

[a-lemus96]

Code the following class members:

• [x] __init__
• [x] render_rays
• [x] render_poses
• [x] init_estimator
• [x] step
• [x] methods for using estimator

[a-lemus96]

This is the list of required parameters for __init__ method:

• train: bool = False for disabling gradient computation
• white_bkgd: bool = False for setting either dark or white bkdg
• chunksize for rendering larger batches

For OccGridEstimator object initialization:

• render_step_size
• near and far for setting sampling bounds along rays
• grid_resolution
• grid_nlevels
• aabb for axis-aligned bounding box

[a-lemus96]

Temporary disabling occlusion regularization by commenting corresponding code block.

[a-lemus96]

I will remove the device parameter inside the Renderer class as the object will be moved to CUDA device.

[a-lemus96]

estimator initalization is performed within __init__ method as it only requires one line.