- With an ESM import the top-level object is a Module Namespace Object
  (https://tc39.es/ecma262/#sec-module-namespace-objects) that has no
  prototype. For compat, Node.js assigns the usual CommonJS
  module.exports to `<module>.default`, so use that when this is
  an ESM module.
- Also, TypeScript translates class properties to assignments in the
  constructor after the super() call. Because super() can call init()
  and enable() synchronously, it calls back into
  'IORedisInstrumentation' before 'traceSendCommand' was defined.
  Defining it as a method fixes that issue.

Fixes: open-telemetry#1692