[Tracker] Indexer

[ross-weir]

Perf

• Insert multiple events per query instead of one by one
• Use list GET events from ledger instead of one by one (requires a endpoint added to ledger with pagination)
• Perform http requests concurrently
• If there's no events being emitted over websocket it can slow down indexing as the events over websocket are used as an indicator of the latest event number, so it could delay us retrieving newer events done Index even if no rollup event websocket messages #132
• Benchmark query that finds missing numbers to be backfilled, it seems like it should be OK though

Extensibility

TBD, what does extensibility in this package look like?