Add a method to reset BandwidthCounter

[kpp]

BandwidthCounter::Clear would be very useful to drop all previous data and start from the beginning. Restarting ipfs daemon is not a solution for all cases.

@Stebalien I can do that but I need help. Would you please guide me how to do this?

• Add methods to clear stats Add methods to clear stats go-flow-metrics#10
• Add API to reset bandwidth counters Add API to reset bandwidth counters #71
• Expose reset as part of the interface chore(metrics): expose reset as part of the interface #72
• chore(metrics): expose reset as part of the interface #72 (comment)
• Release go-libp2p-core
• Release go-libp2p
• Release go-ipfs

[Stebalien]

Fixed.