Confusing feedback when loading Burrito UI with lot of layers

[dixneuf19]

When loading Burrito UI with a lot of layers (50+ in my case, and it will keep growing), the backend requests to get all layers takes more than 8 seconds. While the current CPU/Memory requests of my instance might be a bottleneck, the interface feedback is very confusing

• it display that there 0 layers, leading to think that all my layers have disappeared
• there is no loading indicator, which would hint that I should just wait

Furthermore, the current implementation of the backend requests, without any pagination might not be scalable. Event with a loading indicator waiting several seconds is not a pleasant experience

[marcantoinegodde]

I think we should consider this issue resolved and open a new enhancement issue to add layers pagination later. @Alan-pad