GitLab

* Distributed Lookup service which is for retrieving global_nids to shuffle-global-nids/partition-id mappings

1. Implemented a class to provide distributed lookup service
2. This class can be used to retrieve global-nids mappings

* Code changes to address CI comments.

1. Removed some unneeded type_casts to numpy.int64
2. Added additional comments when iterating over the partition-ids list.
3.Added docstring to the class and adjusted comments where it is relevant.

* Updated code comments and variable names...

1. Changed the variable names to appropriately represent the values stored in these variables.
2. Updated the docstring correctly.

* Corrected docstring as per the suggestion... and removed all the capital letters for Global nids and Shuffle Global nids...

* Addressing CI review comments.