Progressbar for ESO get_header

I am working on a package that requires downloading a lot of headers for files from the ESO archive, which can take quite some time. I was wondering what the astroquery stance on progressbar utils is? Getting a progressbar would be very easy for this function by simply wrapping the for-loop in astroquery.eso.core.get_headers with the tqdm package and adding an additional keyword, e.g. "progress" to the function to toggle this (that's what I do in my local install). The only code line that needs to be changed is 572:
`for dp_id in product_ids` -> `for dp_id in tqdm(product_ids)`

However, this requires adding tqdm as a dependency. I'm sure there are many parts of astroquery that would benefit from having a simple progressbar, but I don't know what astroquery's policy for adding dependencies is.

Start in astroquery.eso.core.get_headers at the loop around line 572, and review how product_ids are downloaded. Check the project's dependency policy and determine whether a progress option using tqdm is acceptable; done means the proposed behavior and dependency choice are settled and documented in the implementation.

Written by the indexing model from the issue text.