fix: tighten up Object.values and Object.entries types

[uhyo]

closes #40

This fix tightens up Object.values and Object.entries types so that:

• Object.values({}) returns unknown[] (previously never[])
• Object.values({ foo: 123 }) returns unknown[] (previously number[])

To get non-unknown[] results you need to pass a value of type Record<string, T>.

const obj: Record<string, number> = { foo: 123 };

Object.values(obj) // number[]

This isn't still perfect but less unsafe than before.