Handle missing output field in Ethereum trace results

[JunaidCD]

Problem

Graph Node fails to deserialize traces when the result.output field is missing.

This occurs for certain trace types (e.g. suicide) where the RPC response legitimately omits the output field, leading to errors like:

data did not match any variant of untagged enum TraceOutput

Cause

After switching to alloy, the output field is treated as required during deserialization, while some valid traces do not include it.

Solution

Before deserialization, a default value ("0x") is inserted when the output field is missing.

Scope

• Localized change in ethereum_adapter.rs
• No changes to external dependencies

Impact

Prevents indexing failures for chains that return traces without output, restoring compatibility with existing RPC behavior.