Suggestion: Keep state of addon window regardless of window closing

[sandersantema]

The bukubrow addon window is automatically closed by firefox if focus is lost i.e. when you change your volume and a hud pops up, after which bukubrow loses its state and the bookmark you were for instance in the process of adding is lost.

Better would be to at least save the state of the bukubrow add bookmark window (assuming saving the state of other windows might be less useful) and only closing the add bookmark window when the user presses on the back arrow or the add bookmark button.

Follow up of: samhh/bukubrow-host#33

[RichardJActon]

I've had the same issue with the bitwarden extension I wonder if this is a generic issue for Firefox extensions?