Adding json format for import

[mathispernias]

• [x] Tests pass
• [x] ruff format
• [x] README.md updated (if relevant)
• [x] CHANGELOG.md entry added

[jochenchrist]

This implementation looks like it supports JSON files with single structures. In practive, we often see JSON files with new line delimited entries that contain 1000 messages.

Example: https://github.com/datacontract/datacontract-cli/blob/main/tests/fixtures/s3-json/data/inventory/year%3D2022/month%3D04/day%3D20/hour%3D00/inventory%2B0%2B0001327496.json

Can you please make sure that the JSON importer also supports JSON documents with multiple entries?

[mathispernias]

The JSON importer can now also takes NDJSON (Newline-delimited JSON).

[simonharrer]

I like it. Can you make the test jsons a little smaller? And make sure the test jsons and their imported contracts have the same file prefix.

[mathispernias]

I updated the JSON tests to include three cases—simple JSON, complex JSON, and NDJSON— I also changed the file prefix.

[simonharrer]

thanks for the contribution!