feat(l2): erc20 load test

[fkrause98]

Motivation

We were missing an I/O intensive benchmark, our first guess is that an ERC20
transfering benchmark should suffice for this.

Description

• Add new erc20 command for the ethrex_l2 test command.

Closes #1999.

[github-actions]

| File                                                               | Lines | Diff |
+--------------------------------------------------------------------+-------+------+
| /home/runner/work/ethrex/ethrex/cmd/ethrex_l2/src/commands/test.rs | 410   | +200 |
+--------------------------------------------------------------------+-------+------+

Total lines added: +200
Total lines removed: 0
Total lines changed: 200

[Oppen]

Just to be sure, where does this binary come from? Is it code you wrote, compiled? Otherwise, what's its license?

[fkrause98]

This binary is the artifact resulting from the compilation of the ERC20.sol + deps.sol files (you can double check it using the solc compiler).

The used libraries are all MIT and properly accounted for: check the deps.sol file and you'll see.
Plus, I left a comment in test.rs linking to the tutorial I've used to generate each of these files.

[Oppen]

Ahh I'm guessing yes.

[jrchatruc]

Let's move the solidity source code and its compiled binary to the test_data folder like I did on #2090; given the load tests are not just for L2 it's probably better to just have them on that directory

[jrchatruc]

Also let's add a makefile target like in #2090 that runs this new load test on "default" settings so it's easy to do a quick run