Default web worker URL to online version

[SheepTester]

https://canary.discord.com/channels/@me/818068592708550696/849688330505682946

If the user's on a file:// URL or maybe if loading the local web worker fails, then try the online version

[SheepTester]

This is a bit complicated because it's loading the Web Worker using some webpack plugin, so we don't have direct access to the URL

https://github.com/SheepTester/scratch-vm/blob/dd071464816ebb7a7b9f757c8d58edbad5b8f876/src/extension-support/extension-manager.js#L159-L165

[SheepTester]

This might get even more complicated because the HTMLifier relies on parsing the bundled code to splice in worker code from a string

https://github.com/SheepTester/htmlifier/blob/55590b15b444d9e0c9d295439367a6da2268711e/hacky-file-getter.js#L222-L249

[SheepTester]

Well, that sucks

[SheepTester]

Hmm, perhaps it could be loaded using the HTMLifier's way of URL.createObjectURL'ing the worker code, but this is just getting increasingly hacky

This currently prevents the offline version from using extensions I believe though, so I won't close this