## Description 

* For error tallies, sample by `error_weight`, as defined by the
originating server based on the error type.
* For spam tallies, sample based on sampling weight, a new config
parameter (by default, we will only tally 20% of "all traffic" for spam
policy)

## Test plan 

How did you test the new or updated feature?

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## Release notes

Check each box that your changes affect. If none of the boxes relate to
your changes, release notes aren't required.

For each box you select, include information after the relevant heading
that describes the impact of your changes that a user might notice and
any actions they must take to implement updates.

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