SegmentIdentity schema display name needs improvement.

## What are the schemas that are affected by the issue
context/segmentIdentiy.schema.json

## What are examples of products that are impacted by the issue
Campaign

The current display name is "Identity" it currently conflicts with the /context/identity.schema.json display name and is causing confusion.

Start by opening context/segmentIdentiy.schema.json and compare its display name with context/identity.schema.json. Check the Campaign example named in the issue and confirm that the SegmentIdentity schema has a distinct display name that no longer conflicts with Identity.

Written by the indexing model from the issue text.