Shift from existing utilities to broader starknet.js usage

Usage related changes

[ ] 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)