Fix userscript and make it auto-updateable

[r3d5ky]

Rename userscript file to .user.js, so tampermonkey and other extensions will detect it and suggest to install it Also changed script to load patch_amazonworker.js and original amazon-ivs-worker.min.js together from cdn, so latest amazon-ivs-worker will be downloaded and "patched" on the fly. This will work until there is a major change in amazon-ivs-worker and the patch stops working with it, and then only the patch needs to be updated.

[besuper]

Hi, thank you for the contribution! Everything looks good, I merge.