feat(l1): add import-bench command for benchmarking block importing

[fedacking]

Motivation

This pr aims to add a consistent command we can use to reproducible benchmark the speed of ethrex, without p2p and other concurrency problems enabled.

Description

• Adds an import-bench subcommand to import blocks and execute them

[github-actions]

Lines of code report

Total lines added: 129
Total lines removed: 0
Total lines changed: 129

Detailed view

+--------------------------+-------+------+
| File                     | Lines | Diff |
+--------------------------+-------+------+
| ethrex/cmd/ethrex/cli.rs | 761   | +129 |
+--------------------------+-------+------+

[fedacking]

We should print the actual execution time based without taking into account the background thread. Then we should print how much we're waiting. Print as "stall on background task"