Concat only unique fields in DatasetInfo.from_merge
Hi @mariosasko,
Just came across this PR and I was wondering if we can use
`description = "\n\n".join(OrderedDict.fromkeys([info.description for info in dataset_infos]))`

This will obviate the need for `unique` and is almost as fast as `set`. We could have used `dict` inplace of `OrderedDict` but it's available 3.7+ onwards Hi,

let's see what @lhoestq thinks. Although my approach adds more code, it's more readable IMO. Yeah, that's true. Your approach is more readable.
I thought someone from the community with less experience would be interested in fixing this issue, but that wasn't the case.

Fixes #2103 