Add metric some transactions' metrics in preparation of a performance work

[ahamlat]

Before we start some performance work, it might be helpful to gather more data. This can help us decide if it's worth starting the project. I suggest we add these measurements:

• How many transactions are in each imported block

• How much gas is used by each imported block

• What percentage of transactions in the imported block are "remote confirmed". We can figure this out the existing metrics and the ones above.

• What percentage of the total gas used in the imported block is from "remote confirmed" transactions. We can also figure this out from the above metrics.