Hard-coded min fee not works in private network or test network

Indexer hardcode min fee in static distribution code.
It works for the CodeChain Main network, but not works for test networks or private networks.

https://github.com/CodeChain-io/codechain-indexer/blob/4a4006a66eadce67bd6214e94dc2d73d849bd741/src/worker/staticFeeDistribution.ts#L117

Indexer queries the min fees in the dynamic fee calculation. It seems that (not confident) CodeChain before 2.0 does not have a feature that queries the min fee.