Feature request: Sync in archive mode starting from a certain block

[varasev]

For Ethereum Mainnet (and other supported chains) we need to have an ability to start syncing in archive mode beginning from a certain block which number is defined in the config. This assumes that the node should be synced from scratch as a full node, but at some point would switch to archive mode (like we'd activated --pruning=archive and --fat-db=true options).