Emit `object` for Web IDL `object` types?

[saschanaz]

This generator has been treating object as any ever since it's created in 2017: https://github.com/microsoft/TypeScript-DOM-lib-generator/blame/317c27a36a49528e86f6f16ab8f01f3239f80ea0/TS.fsx#L719

But in the same year TypeScript introduced object type: https://devblogs.microsoft.com/typescript/announcing-typescript-2-2/#the-object-type

In #2459 I got a reason to make it actually object, since Origin.from() should ideally receive object | string. (That's still not the most strict type, but I don't think we can do anything more than that.)

@jakebailey Thoughts about any reason we should not do this?

[jakebailey]

Other than backwards compat, I don't see a problem? I think I'd need to see a diff to understand the breakage, and run extended tests and see.