Add native author to indexed fields

[aaccomazzi]

Some publishers provide a "native" author field, which is the name specified in the native language of the author, usually chinese or greek characters.

We should check and see whether the ADSimportpipeline captures this from ADSExports.

[JCRPaquin]

@aaccomazzi is this still an issue we want to pick up?

[aaccomazzi]

@ehenneken are we populating this field in ADSExports?

[ehenneken]

We are: https://github.com/adsabs/adspy/blob/master/ADSCachedExports.py#L922

[aaccomazzi]

@JCRPaquin yes, let's add this to the list of schema enhancements.