[CLI Feature] Snark stats, snarks-per-second

On the status screen show the estimated SPS (Snarks-Per-Second) for the entire snark-worker network.

If you are running a snark-worker show also the SPS metric for your own worker.
Also include some additional information about the total number of transaction snarks you have solved and the length of the queue.

coda client status

Coda Daemon Status 
-----------------------------------

Global Number of Accounts:                     18
The Total Number of Blocks in the Blockchain:  1
Local Uptime:                                  36s
...
Snarks per second (network, 24hr):             3.14
Snarks per second (local, 24hr):               0.032
Snark-worker queue:                            271
...

discord: jspadave