Reduce stack footprint for error handling

The error handling changes in #2544 result in a large stack footprint due to:
1. Many arguments passed to error mapping functions
2. Growing size of `ExecutionError`

Potential solutions:
- Re-introduce `ErrorContext` as a struct passed by reference (reduces argument count)
- Box inner error types (reduces `ExecutionError` size)

Note: Boxing is not trivial since `Diagnostic` is not implemented for `Box`.

See [comment](https://github.com/0xMiden/miden-vm/pull/2544#issuecomment-3724332474).