Optimize VOTable building process
Currently, the VOTable output relies on Astropy (and numpy) : https://docs.astropy.org/en/stable/io/votable/
As some methods are missing (or misunderstood) in the API, the current workflow is :
- create a VOTable object in memory
- add a row to this table for each result
- writing the whole structure into a file
- reopen the file and read the content to serve it through the response object
The process could be more efficient using a file stream pattern