POC - Handle when Worker is unsupported

[Conrad2134]

This is to show that falling back to the main thread when Workers aren't supported works. There's a lot of TODOs because I wasn't sure the best way to go about a couple of things.

Bundles:

878 B: workerize.js
877 B: workerize.m.js
941 B: workerize.umd.js