Create settings.js file

[0reo]

Getting/setting graphics settings should be handled via settings.js file, as suggested in #2512. Reference is below.

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1. Is there ever a need for an app to be setting this? It's an abusable feature (imagine a world that forces quality against your settings) so I don't want to make it easy for apps to override this.

2. Any such getter usually needs an event system (EventTarget). Otherwise how are you going to update when it's changed?

3. This should not be owned by metaversefile. These settings should be in settings.js, which exports an EventTarget and abstracts the local storage aspect, rather than littering it across many files in different directories. And the UI should use settings.js so it's one point of control, not different apps with different ideas of what setting are.

Originally posted by @avaer in #2512 (comment)