Allow user to toggle extra google api scopes

[thdk]

User should be able to decide if he/she/x wants to authorize the timesheets app to look into the google calendar for items that can be suggested to be added into the timesheets.

Interesting article on how to add scope for google calendar api into firebase authentication.
https://medium.com/google-cloud/using-google-apis-with-firebase-auth-and-firebase-ui-on-the-web-46e6189cf571