## Description 

Decouples ingestion and benchmarking, remove the benchmark related code
from sui-indexer crate.
After this change, we will always first run synthetic ingestion to
generate a workload, and then separately, run indexer to benchmark it.
This has a few benefits:
1. We no longer need to maintain compatibility between indexer and
indexer-alt in terms of benchmark integration. This is good because it
is a lot easier to benchmark indexer-alt, since it supports stopping at
a specific checkpoint.
2. This will make it easier to use different types of ingestion
workload.

Also cleaned up the ingestion generation code by allowing generation
from checkpoint 0, and made sure that every checkpoint has the same
number of transactions.

## Test plan 

Updated tests.
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## Release notes

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- [ ] Protocol: 
- [ ] Nodes (Validators and Full nodes): 
- [ ] Indexer: 
- [ ] JSON-RPC: 
- [ ] GraphQL: 
- [ ] CLI: 
- [ ] Rust SDK:
- [ ] REST API: