Client side timeout handling, and other improvements

[koresar]

• Drop support of Node 18 and below. Only 20 and above is supported. This unlocks a number of simplifications.
• Remove node-fetch as a peer dependency. Rely on the built-in fetch().
• Drop aws-sdk v2 peer dependency. Use the lighter v3 module @aws-sdk/lambda-client
• Relax 2 of peer dependency versions: Express and BullMQ.
• Replace ESLint with OXLint because it needs no configuration.
• Replace Mocha with node:test
• Implement client-side timeout handling. (That one was tough.)
• BREAKING: LambdaTransport might not work with previous one. It depends on the freshness of your Allserver module.