Add structured metrics for transaction execution outcomes

Description

Improve transaction execution observability by exposing structured metrics that distinguish successful executions from reverted, failed, and otherwise rejected transactions.

Motivation

Transaction execution failures are important when diagnosing node behavior and application-level issues, but aggregating outcomes into a small number of clearly defined metrics would make it easier to identify failure patterns without inspecting individual logs.

Proposed change

• Identify the appropriate execution path where transaction outcomes are finalized.
• Add metrics that count the relevant execution outcomes using the repository's existing metrics conventions.
• Ensure metrics are updated exactly once per transaction outcome.
• Add unit/regression tests covering the success and failure paths.
• Keep the change scoped to execution observability; do not alter consensus or transaction execution semantics.

Acceptance criteria

• Metrics accurately distinguish the documented transaction outcome categories.
• Existing execution behavior remains unchanged.
• Tests verify metric updates for representative success and failure cases.
• The implementation follows existing Geth naming, registration, and testing patterns.

Scope

Intermediate-level Go contribution involving code navigation, existing metrics infrastructure, execution flow, and regression testing.

Repository: Go Ethereum (Geth), the Go implementation of the Ethereum execution layer. fileciteturn0file0L100-L106