Improve testability by injecting analytics in `OrderDetailsViewModel`

[iamgabrielma]

Currently there's 25+ calls to ServiceLocator in OrderDetailsViewModel that are mainly used for tracking events. We should inject the analytics provider directly rather than reaching for the shared instance.

This also causes that track events have to be tested with setups like:

let analytics = ServiceLocator.analytics.analyticsProvider as! MockAnalyticsProvider