Added licenses (#89)

* added a few licenses with link to verify and license column in all.

* added license for the RGB + Depth datasets

* added license of the RGB datasets.

* updated the CMU Panoptic note.

* updated the weblink from the NYU dataset. it has been moved from the old link, the old link will refer to the Access denied page.

* added depth datasets license where possible.

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Co-authored-by: Rohit Kumar <[email protected]>