debug_trace*: emit struct-log refund and returnData fields

[manusw7]

Is your feature request related to a problem? Please describe.
After #12056 aligned the default debug_trace* opcode (struct) tracer with execution-apis#762, two optional struct-log fields are still not emitted, leaving Nethermind short of the geth/Besu/Erigon/Reth default output:

• refund — the accumulated gas-refund counter per step (others emit it when non-zero). This is the one field where Nethermind still diverges from the cross-client default.
• returnData — per-step return data (others emit it only when enableReturnData is set; off by default, so omission is currently conformant).

Describe the solution you'd like
Emit both in the streaming (GethLikeTxDirectStreamingTracer) and in-memory (GethLikeTxMemoryTracer) tracers:

• refund: include when non-zero, as the cumulative refund counter at each step (matching geth's pre-op GetRefund()).
• returnData: include only when the enableReturnData flag is set.

Describe alternatives you've considered
Both fields are optional in execution-apis#762, so omitting them is spec-conformant — but emitting refund would match the cross-client majority.

Additional context
Deferred from #12056 because Nethermind exposes only per-op refund deltas via ReportRefund (no cumulative counter, no roll-back on reverted frames) and no per-step return-data buffer at the op-level hook, so both need EVM plumbing to implement correctly. Reference: go-ethereum eth/tracers/logger/logger.go.

[0xDevNinja]

Picking this up. Will emit refund (cumulative counter, non-zero) and gate returnData on enableReturnData in both the streaming and in-memory geth struct tracers.