Optimize dedup function in API

[annelhote]

• Use reduce func https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reduce ?
• It might be due to the merge func ?

[annelhote]

Search "universite de lorraine", between 2018 and 2022 :

• Before: 2:54.299s
• After: 216.207ms => prefer reduce instead of forEach