[Feat]: Remember password across browser session restarts

## What is your suggestion?
I have a fairly complicated password on my code-server instance, and every time I restart my device (a Chrome OS laptop from my school) I have to log back in to my instance. It would be nice if code-server always remembered my password, or at least a period longer than across computer reboots.

## Why do you want this feature?
So I don't have to keep typing in my long password.

## Are there any workarounds to get this functionality today?
No

## Are you interested in submitting a PR for this?
Not likely as I don't do much work with JavaScript, though I'd be open to it if it isn't overly complicated.