Add support to search for region

[nlegoff]

Given a city is indexed in "ile-de-france" region
Looking for ile-de-france returns 0 result

[romainneutron]

do you have a use case where it's useful ?

[nlegoff]

You told me that orally 2 days ago ...

[romainneutron]

We need use cases ; for example Paris, texas should return Paris, Texas, USA