Shift from existing utilities to broader starknet.js usage

[penovicp]

Usage related changes

• TODO
• ...

Development related changes

• TODO
• ...

Checklist:

• [ ] Formatted the code
• [ ] No linter errors + tried to avoid introducing linter warnings
• [ ] Performed a self-review of the code
• [ ] Rebased to the last commit of the target branch (or merged it into my branch)
• [ ] Documented the changes
• [ ] Updated the test directory (with a test case consisting of network.json, hardhat.config.ts, check.ts)
• [ ] Linked issues which this PR resolves
• [ ] Created a PR to the plugin branch of starknet-hardhat-example:
  • < EXAMPLE_REPO_PR_URL >
  • [ ] Modified test.sh to use my example repo branch
  • [ ] Restored test.sh to to use the original branch (after the example repo PR has been merged)
• [ ] All tests are passing (for external contributors who don't have access to the CI/CD pipeline)

[FabijanC]

Aside from this PR now hving conflicts with master, it is also in conflict with #414