Add Support for Multiple pictures of same receipt

[pranavpsv]

Add support to Receipt Parser Endpoint such that a person is able to upload multiple pictures of same receipt if receipt is too long.

[pranavpsv]

One naive solution is to remove duplicate items after combining receipt parser result of two different pictures. However, there is the edge case when same item appears multiple times in receipt. For instance, OCN SPRY JCE and SUPER SAVER appear multiple times in the following receipt:

Hence, removing duplicate items might not work since the repeated items might not be duplicate.