Improve first sync

[RiccardoM]

Feature description

We should find a way to improve the first sync of BDJuno. This can be done for example via the export of the current state chain and then using the genesis_file_path field to provide BDJuno a starting point. However, this will loose all the historical data such as:

• Proposals that did not pass
• Voting power snaphots after a proposal passes

Implementation proposal

To solve this, we could create a list of things that are deleted from the chain state (eg. proposals that did not make it into voting period) and get them using the tx_search endpoint by searching for specific messages.