Introduce a custom enum for ExEx WAL errors

[shekhirin]

Describe the feature

Currently, we use eyre::Result for errors in ExEx WAL, but we can do better with a custom thiserror-powered enum that has rich variants (with tuples/structs) to pass additional fields such as file_id.

https://github.com/search?q=repo:paradigmxyz/reth+path:crates/exex/exex/src/wal+eyre&type=code

Additional context

No response