See https://github.com/python-babel/flask-babel/releases/tag/v3.0.0
rebased onto 3ca0319cda24c9bd2997a02b9c5c0f6eb37c84b5
rebased onto 2f0b7be41515ee64ed0b1e485c7ba40292b72fca
Pull-Request has been merged by humaton
See https://github.com/python-babel/flask-babel/releases/tag/v3.0.0