This commit replaces window.mailpoet_tracking_enabled variable with
tracking config object that carries the level and configuration for
all tracking options (emailsTrackingEnabled, cookieTrackingEnabled).
The window.mailpoet_tracking_enabled is confusing since it is not obvious what type of tracking is enabled.
[MAILPOET-3185]
We introduced new settings that enable set different levels (basic, partial, full) of user tracking.
Each level enables different tracking options. This service should encapsulate the logic that determines
what should be tracked on each level of the setting.
[MAILPOET-3185]