fix(ethereum): handle trace_filter traces missing result.output via c…

[ibrahim1023]

Summary

Fixes #6489

This PR fixes a regression where trace_filter responses fail to deserialize when a trace result is missing the output field (for example, some Sonic traces), causing repeated retries and trace ingestion failure.

Root Cause

Graph Node now uses Alloy trace types for trace_filter responses. Some providers return traces where result.gasUsed is present but result.output is omitted. Alloy deserialization treats that as an invalid TraceOutput variant and fails the entire response.

What Changed

• Kept the normal typed Alloy trace_filter request path unchanged for healthy responses.
• Added targeted detection for the known deserialization error:
  • data did not match any variant of untagged enum TraceOutput
• Added a compatibility fallback path only for that error:
  • re-issue trace_filter as raw JSON
  • patch traces with missing result.output by injecting "output": "0x" when result.gasUsed exists
  • deserialize patched JSON back into Vec<LocalizedTransactionTrace>
• Added/updated regression coverage in ethereum_adapter tests for:
  • reproducing the original missing-output deserialization error
  • verifying the compatibility patch injects result.output

Why This Is Safe

• The fallback is narrow and only activates for one known error signature.
• Normal successful responses stay on the existing typed path.
• Patch logic is minimal and scoped to trace entries where result already indicates execution output context (gasUsed) but output is omitted.
• Existing parsing/trigger logic remains unchanged.

Validation

Executed locally:

• cargo test -p graph-chain-ethereum missing_output_trace_repro -- --nocapture
• cargo test -p graph-chain-ethereum

Result: all tests passed (50 passed, 0 failed for graph-chain-ethereum).