Feature request - indexer agent reset / export / import

[koen84]

Would be good to have extra options for

graph indexer rules reset
graph indexer rules export
graph indexer rules import

There might be times you want to start with a fresh slate, in testnet as well as mainnet. Reset would revert status to the default rules that come with it. Before reseting you might also want to create a backup. A backup is also useful if you need to migrate machines (export + import) or want to revert to a previous state.