[Feature] Add usage stats

[zbruceli]

Is your feature request related to a problem? Please describe.
It would be really useful to add usage stats to Surge client, e.g. showing how much bandwidth I have used both for uplink and downlink, which files that I seeded gets requested etc.

Also it will be useful to have some kind of leader board for remote files: which file is most seeded, which file is most downloaded, etc.

Describe the solution you'd like
A clear and concise description of what you want to happen.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.