FR: Visualize how exit nodes are being used in admin console.

### What are you trying to do?

I have few users in tailnet and some exit-nodes, I want to know how, the status, the exit node is being used. E.g at a specific period how many user is using the exit-node, how much data is sent. What is the load status of the gateway machine.

Some of the exit node is powerful and some are not, and some has a maximum data usage per month. With this I can inform user what exit is recomended to use.

### How should we solve this?

Log exit node usage satus to admin console. A map that can visualize ongoing connections, or a table. Indicating what exit-node has the highest load. Or a option to load balance the exiting traffic.

### What is the impact of not solving this?

I have to manually inform user what exit-node is recommended to use for faster response and best speed.

### Anything else?

_No response_