Support for custom consensus on private networks

[scholtz]

Summary

Algorand indexer at the moment does not allow using custom consensus on private networks. This pull request adds this feature.

Test Plan

I tested it manually on custom made private network with custom consensus.

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[Eric-Warehime]

Hi, I'm not sure if I can see what this would do since block data in the indexer is imported independent of the consensus process. Can you give me a bit of background on why you might need this change?

[scholtz]

hi @Eric-Warehime

sure, algod loads correctly custom consensus from consensus.json file.

but there is no way to use custom consensus with the indexer..

the indexer without this bugfix fails here https://github.com/algorand/indexer/blob/5be3c0e17e455b037a05c941b305a4378b420d55/importer/importer.go#L27 with error protocol 'custom-protocol' not found

if you want, you can find the way to load consensus from the algod server, but right now you are using hardcoded consensus values with no option to extend it.. this PR is simple fix to resolve the issue with ability to provide consensus.json file with the indexer

[Eric-Warehime]

Thanks for explaining, @scholtz 😁