Add option to optimize for maximum query fees

[alex-pakalniskis]

Indexers would like a decision-support tool to help them optimize for query fees on the network. I propose adding such a feature to the allocation-optimizer tool.

Based on the allocation-optimizer docs there are some data availability-related blockers to optimize for query fees directly (see below).

We do not optimise for query fees directly, as we expect signal on a subgraph to be proportional to the query fees, as was the intention behind curation. Query fee information is also not public. It is local to each gateway. As a result, we will never be able to optimise with respect to query fees unless this changes.
-https://graphprotocol.github.io/allocation-optimizer/latest/

Are there "indirect" optimization methods we could explore?

Finally, optimizing for query fees would be a nice addition to an allocation optimizer UI (see #44)