[Draft code] average gas improvements

[josojo]

Not intended to merge. Just researching...

I was looking into the gas-checker a little bit - since I had a genuine interest in seeing the real numbers - and found out that it is really not reliably working.

E.g. it returns:

num_trades, the average gas overhead per settlement
1.0    1.099626
2.0    0.985675
3.0    0.983962
5.0    0.981078
6.0    0.549295

Which is very unrelalistic.
But I could not really find the root cause, though there are several factors that might be important:

• The gas estimations from the price estimators are really just estimations and sometimes they have an additional buffer
• The price estimation only returns the quotes with the best prices, but not the quotes with the highest return for the user - outamount - gas fees.

[bh2smith]

FYI - these fields are all Optional now with defaults essentially as you have specified here (empty parameters and mainnet and empty string for name). No need to change here, just thought you might like to know about these recently added conveniences.