Display RPC nodes latency in test-dapp

[hui-an-yang]

In taquito-test-dapp users only have the choice of different networks to connect to, and the rpc URLs are hard-coded to be ecad ones for now.
Would be nice to display a list of different rpc node URLs (diff providers) with latency info by the chosen network for the user to choose from before connecting
Once connected to the wallet user can click on settings to choose networks and display a list of rpc URLs with latency info of the chosen network to switch to
Ideally, when the page is loaded, we ping various rpc URLs of the default network(ghostnet) to get the latency info
If the user chooses a different network a list of rpc URLs of the chosen network with latency will be displayed to choose from
Also, when the setting button is clicked ping again to get the latest latency info
Before the latency info is back would be good to display something like loading/fetching
If no success fetching a response from an rpc for more than 1? minute might mean that the rpc node is down (display timeout?)
rpc endpoint to ping /chains/main/is_bootstrapped

nice to have: ping the rpc URLs frequently to keep the latency info in real time