Unexpected re-renders when the saved cookie is an object

[albertodeago]

Hello!
First of all thanks for the library, I'm using it since ages and it's an amazing one.

I think I've found a possible issue, let me try to explain it:

The shouldUpdate function is used to check wether the component will rerender with a new value, the problem is that if the cookie is an object (e.g. {"key": "value"}) that shouldUpdate function will always return true as the === will always resolve to false because the object references are going to be different between cookie reads.

This may seem not a problem, but, every time one cookie change (let's call it cookie-1), all the listener of useCookies occurrences will fire, so if I used three times useCookies in my app, like:

// component 1
...
const [c, setC] = useCookies(["cookie-1"]);


// component 2
...
const [c, setC] = useCookies(["cookie-2"]);


// component 3
...
const [c, setC] = useCookies(["cookie-2"]);

All three 'listeners' will fire, and the shouldUpdate function will run three times (as expected).
The problem is that, if cookie-2 or cookie-3 are object values, that shouldUpdate function will return true and cause a re-render of the component, even if we actually just changed cookie-1

This is a repo to easily reproduce it, the readme have all the steps to do it:
https://github.com/albertodeago/react-cookie-repro-obj
(I created the repro with next.js because it was faster, but it's not next.js related)

I'm happy to open a PR to fix this, if you agree with me this is an improvement.