feat: add fallback nodes to provider

[piwonskp]

Motivation and Resolution

Resolves #872

RPC version (if applicable)

Usage related changes

Development related changes

Checklist:

• [x] Performed a self-review of the code
• [x] Rebased to the last commit of the target branch (or merged it into my branch)
• [x] Linked the issues which this PR resolves
• [x] Documented the changes in code (API docs will be generated automatically)
• [x] Updated the tests
• [x] All tests are passing

[ivpavici]

My initial idea for this was to dedicate to one and switch to the next when it fails

I thought of the same approach as you said here, I think Ethers works like this, but I have to double check. I think if we want to go with this approach it wouldn't be a big change in this PR

[tabaktoni]

Another option is to create n channels for each provider

[tabaktoni]

TODO: I would like to refactor this approach and will do on the same PR