[Tree perfs] When the tree is opening: reduce API calls or replace with lighter calls
When we have a big tree with many opened items, each node make an API call to /api/v1.0/node/ (and potentially other callbacks).
Dozens of simultaneous calls require a memory peak in the frontend, which causes the browser to freeze, and all Gargantext is unusable.
Sometimes a browser tab can take up 2G of memory.
(This issue is related to #669 (closed) because that the way we found the side effect)