Bilateral Filtering Directly on DepthAI

[Luxonis-Brandon]

Start with the why:

For readily available smooth point clouds, and for overall better depth and object detection 3D localization, bilateral filtering seems to do a good job (see comparison w/ no filtering and WLS, here: fixstars/libSGM#20 (comment)). And it seems reasonably possible to implement this directly on DepthAI so there is no host load (just as we have Median filtering size now w/ a variety of kernel size options). This will likely pair quite well with subpixel support as well (#163) and will also likely result in better point clouds as in #180.

Move to the how:

Leverage the SHAVES to support optional Bilateral filtering on DepthAI directly as an option (just as Median is now).
This Bilateral filtering will be useful for other applications than just depth. So we should implement it as a #136 node so that it can be generally applied.

Move to the what:

Support Bilateral filtering node that is usable for filtering depth directly on DepthAI.