feat: add load testing with async and parameterized features

[fborello-lambda]

Purpose

• Add a way to generate multiple transactions with randomWallets to replicate a real world scenario.
• The gas calculations could be moved to another PR, so that it can be reviewed without to much effort.

How

The proposed implementation is integrated with the typescript cli, to test the command:

bun run cli.ts load-test -w 1

This will generate one random wallet and it can be used with the dev environment(reth and localhost). To have more information on how to use it:

bun run cli.ts load-test --help

output:

Usage:
  $ cli.ts load-test

Options:
  --l1url <l1url>    ETH chain URL, defaults to localhost dev env 
  --l2url <l1url>    zkStack chain URL, defaults to localhost dev env 
  --pk <pk>          Rich PK, defaults to RETH's rich wallet 
  -a, --amount <a>   ERC20 Amount to send, defaults to 100 
  -w, --wallets <w>  Amount of wallets, defaults to 5 
  -h, --help         Display this message 

Examples:
[dev-env]  load-test
[real-env] load-test --l1url <l1-url> --l2url <zkstack_url> --pk <pk> --amount <amount> --wallets <number-of-wallets>

[ilitteri]

LGTM

[ManuelBilbao]

LGTM