Fix "deprecated" on wrong dataFormat field

[zebdelk]

I was confused by the distinction between dataFormat and dataFormats. Currently dataFormat is marked deprecated, but it should actually be the reverse.

• [ ] update search openapi.yaml to describe dataFormat as a flattened and normalized representation of data format, used for aggregation
• [ ] update search openapi.yaml to describe dataFormats as deprecated.
• [ ] (if applicable) update ES pojo generation (a kotlin file under buildSrc) to reflect deprecation correctly as well
• [ ] make sure I didn't make the same mistake for other deprecated fields