[Tech] Renommer le token du backoffice

The following discussion from !104 (merged) should be addressed:

• @pecarlat started a discussion: (+1 comment)

  nitpick: Oui ça me paraîtrait mieux aussi. Juste mauvais format de commentaire

  # rename this to backoffice token ?

TODO after merge

• Delete variables REC_SGE_API_TOKEN and PROD_SGE_API_TOKEN