BREAKING: support of es module

[myfreeer]

This should be marked as a BREAKING CHANGE, since supporting esm is currently infectious, everything depends on it would have to move to esm after this.
A release must be created before this.

Things to wait for:

• jest with esm support: https://jestjs.io/docs/ecmascript-modules
  • jest.mock
• ts-jest: https://kulshekhar.github.io/ts-jest/docs/getting-started/options/useESM
• node.js: https://nodejs.org/api/vm.html#vm_class_vm_module

Things to change:

• worker-pool.spec.ts (__dirname)
• package-lock-resolved.js (__dirname)
• delay-calc-worker.js (require)
• copy-src.js (__dirname)
• tsconfig.json
• package.json

Things breaking by this:

• p-queue 7.3.4 (build(deps): bump p-queue from 6.6.2 to 7.3.4 #747)
• srcset 5.0.0 (build(deps): bump srcset from 4.0.0 to 5.0.0 #393)
• got 12.6.0 (build(deps): bump got from 11.8.6 to 12.6.0 #763)

[myfreeer]

Maybe we can use rollup to package p-queue to commonjs module again