feat: add type annotations to zksync module

[comilao]

What 💻

• This PR intends to add type annotations to the zksync module
• Fixes Running Tests section in README.md based on this workflow

Why ✋

• As mentioned in this issue, adding an external module by attach_modules does not provide type annotations

Evidence 📷

Before this change, hovering over zksync, it shows

After this change, hovering over zksync, it shows

This provides useful function hints in the code editor

Notes 📝

• Any notes/thoughts that the reviewers should know prior to reviewing the code?

• It's my first PR to the open-source world ever, please be patient with me if I did something wrong. Thank you in advance 🙏

[petarTxFusion]

Could you update this branch with latests changes so that test can pass? Thank you for your contributions

[comilao]

Could you update this branch with latests changes so that test can pass? Thank you for your contributions

Sorry about this.
Actually I am thinking of a big refactor plan.

• isort to sort imports
• flake8 linter to the code base
• black for formatting
• mypy for type hints

All of the above can be put inside pre-commit hook config file. We can update the CONTRIBUTING.md to ask contributors to install it and also add these checks it to the validate.yml GitHub Actions. How do you think about it?

[petarTxFusion]

We are planing to refactor large part of the code in the near future which will resolve typing issues, we are trying to avoid other dependencies as much as possible plan is to use native typing. The main problem lies in the design itself. We are planning to go with External Modules and Custom Providers you can read more about it here

[comilao]

Thanks a lot for this comment. Glad to know your team will be revamping this repo, it really helps me a lot during my work. I have made another PR #68 to explain more about what I mean, sorry for the inconsiderate comments earlier, I can also help with some tasks if you needed help. I will also close this PR first.
(BTW, I'm a QA automation engineer, so if you need, I can help with writing more test cases)