[Feature Request]: Unit Test consider a different file format

### What would you like to happen?

Unit tests currently use CSV files which are unfriendly to Blobs and other text containing commas carriage returns, etc.

Please enable the use of a different file format e.g. avro as a dataset source so that we have a more flexible unit test universe.

### Issue Priority

Priority: 3

### Issue Component

Component: Hop Gui