feat(experimental): Add an env var to limit the max gas price for resends

[arcoraven]

PR-Codex overview

This PR introduces a new utility object BigIntMath for mathematical operations on bigint values, adds experimental environment variables for gas price settings, and updates the _updateGasFees function to utilize these new utilities. Additionally, it includes tests for the new BigIntMath functions.

Detailed summary

• Added BigIntMath with min and max methods for bigint operations in src/utils/math.ts.
• Introduced EXPERIMENTAL__MAX_GAS_PRICE_WEI in src/utils/env.ts.
• Updated _updateGasFees in src/worker/tasks/sendTransactionWorker.ts to use BigIntMath.
• Added tests for BigIntMath functions in src/tests/math.test.ts.

✨ Ask PR-Codex anything about this PR by commenting with /codex {your question}