## Description 

This PR adds a stress test in simtest to test shared object congestion
control. The test is a good catch for liveness issue related to shared
object congestion control.

After creating the test, I manually added some liveness bugs in the code
(e.g. do not remove deferred txn from root, which can cause checkpoint
stall), and the test was able to catch such bugs.

It also found an existing bug that when checking txn objects for
congestion, it doesn't check if the transaction contains shared object
or not.

## Test plan 

The test created in this PR.

How did you test the new or updated feature?

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## Release notes

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