* Add benchmark-block command

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Apply suggestions from code review

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>

* Beauty fixes

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Beauty fixes

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>
Co-authored-by: parity-processbot <>