allow custom algod consensus

[scholtz]

Summary

This pull request allows read consensus.json file.

It is dependant on

https://github.com/algorand/go-algorand-sdk/issues/754

https://github.com/algorand/go-algorand-sdk/pull/755

Test Plan

We built using https://github.com/scholtz/AlgorandNodes/blob/main/docker/indexer/aramidmain/aramid-indexer-3.9.0.sh

and test it on aramid chain directly