Add cors on resource redirect

[maudetes]

Fix CORS missing on stable resource permalink, ex : https://www.data.gouv.fr/fr/datasets/r/503c39b0-58d8-45fe-ace0-55795bb0a6b7.

Indeed, the resource permalink may be used directly in Observable for example for a parquet file.

TODO:

• [X] find a better way to trim lang code
  • could not find a perfect solution but used the optionnal lang code with g.lang_code and trim it with removeprefix
• [X] check CORS on static resources
  • correctly served by nginx