Add clinlp data

[vmenger]

Describe the change

• Moved some real world cases used for testing to /data so it's more accessible
• Made InfoExtractionDataset read and write from/to json

Linked issue
N/a

I have checked my changes are in line with the Coding Standards
Yes

I have added my changes to the CHANGELOG.md file
Yes

Any other relevant information
Add any other context about the pull request here.