Add extension configuration for latest version notification

[LastTalon]

Add a configuration option to provide functionality that was changed in #207. The extension no longer updates the user about updates to the latest version when they have configured the extension to use a different version which some users may still desire.

This adds a boolean configuration option to give users the notification. The notification should not be intrusive to install prompts.

This feature was attempted prior to releasing #207 where a major pitfall was the intrusive nature of double prompting. This would affect all users with the notification enabled. The double prompting is likely too annoying for any users to enable this feature, thus it must not do this.