Allow axios timeout configuration via hardhat config

[notV4l]

Usage related changes

• Close Allow request timeout customization #318
• allow axios timeout configuration via hardhat.config.js

Development related changes

• new parameter in hardhat.config.js

starknet: {
    requestTimeout: 90_000,
}

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]

You should expand test/configuration-tests. No additions would be required to the starknet-hardhat-example repo.

You could introduce two new test cases:
- one with an extremely small timeout (1 ms) and expected to fail
- another with a sufficient timeout (e.g. 30 seconds) and expected to pass