refactor evm metrics collection to only collect metrics about tps

[mattac21]

Note

Simplifies Ethereum metrics to TPS-only via block-level tx counts and trims, and adjusts gas limit buffers (+30% baseline in factory, ~2% estimate buffer in wallet).

• Metrics (chains/ethereum/metrics/collector.go):
  • Refactors collection to TPS-only using lightweight BlockStat (block number, total txs, timestamp).
  • Concurrently fetches blocks, aggregates per-block tx counts, trims empty edge blocks, computes runtime and TPS, and logs concise run info.
  • Removes receipt-based analysis, per-message stats, gas/utilization analytics, and detailed LoadTestResult population (returns empty struct).
• TX Building:
  • txfactory: when using baselines, set GasLimit to baseline + 30% instead of exact baseline.
  • wallet: reduces gas estimate buffer from 1/20 (~5%) to 1/50 (~2%).

^{Written by Cursor Bugbot for commit a9269a8. This will update automatically on new commits. Configure here.}

[cursor]

Bug: Gas Buffer Mismatch Causes Transaction Failures

The gas buffer calculation changed from 5% to 2% (gasLimit / 20 to gasLimit / 50). This reduction contradicts the existing comment claiming a "20% buffer" and significantly lowers the safety margin, potentially causing transactions to fail due to insufficient gas.