Split netflow-traffic code that became too big for a single file

• netflow traffic model has been introduced to manage states
• drawer is now on its own separated component
• overview / table & topology are now under tabs folder with an additionnal tabs container component
• modals are centralized in modals component

Also, move fetch function in their respective components:

https://github.com/netobserv/network-observability-console-plugin/pull/551#issuecomment-2233064292