[Indexer] Orphan Blocks

[rafaeldkb]

• [x] Allow streaming of orphan blocks to s3
• [x] Take into account the block validation depth, so that a block can be considered confirmed only if x number of blocks above it have already been added
• [x] Identify which block is part of the mainnet and which is an orphan block
  • [x] Apply on Streaming
  • [x] Apply on Backfilling
  • [x] Apply on Missing blocks
• [x] Propagate the mainline flag to
  • [x] Blocks
  • [x] Transactions
  • [x] Transfers
  • [x] Balances