Switch userscripts to top-level await

[karlhorky]

Top-level await is supported as of ViolentMonkey 2.19.2+:

• https://github.com/violentmonkey/violentmonkey/issues/833#issuecomment-2185016529

Audit all userscripts and switch relevant userscripts to use top-level await (eg. add-tmdb-links-to-imdb.user.js probably)

[karlhorky]

I wanted to try this out today, but I saw that 2.19.0 is the latest version published in the Chrome Web Store

This can be used via beta, but I think I'll wait until 2.19.2 is published.