Remove the workers in jsutils in favor of functions in src/workers.js, modify the paths to load blob urls of the workers

There are parts from webpack we don't control which start with a /, so we'll go with making sure all our paths prepend a / instead.

This reverts commit ce7da9b2.

Use fixed relative paths. I believe this will work the way we load it, but if it does not we will leverage the global xxdk_base_path to set it explicitly

Update wasm_exec to deal with 1.21 issues, had to define a runtime.Throw and copy the gojs to go in addition to previous changes