Added new Sequencing datasets: API BLEND EVAL

[sadhana01]

Dataset consists of SeqATIS, SeqSNIPS, SeqSGD, SeqMultiWOZ,SeqTopV2.
Added two versions sequencing and sequencing lite with their Licenses .
Added code changes pertaining to the two datasets.

SeqTopV2 full dataset is missing since it is too big and Git LFS on github.com does not currently support pushing LFS objects to public forks. (To be discussed)

[ShishirPatil]

Thanks for the PR @sadhana01

1. There are different License files in the PR :) This is one too many. Also BFCL and the entire Gorilla project is already under a License which applies to the entire directory so we don't need these files?
2. Maybe we can move the data files (jsons) from each category into the data/ sub-directory? We have organized all the data files into a single directory. The good thing is that the files already have the name SeqATIS etc so just moving them there should be good?
3. I'll slowly review each of the rest sequentially since there are quite a few of them. Done reviewing

[sadhana01]

@ShishirPatil They are different licenses for each dataset (3 different). I had initially put all the data files under the data folder. However I was advised by lawyers to include the license for each dataset which is why I created subfolders for them . We can discuss the best way forward .