local storage optimization

[pritipsingh]

We don't really need local storage in the client side as we're already storing it in the extension side using:

And we're also storing it in client side like this:

The other approach would be on Clicking handleFocusTime we can send the values of end, start or value of focus toggle to background script and to show it in the extension we can fetch it directly from there using the chrome's send function from background to popup.