Allow custom properties for screen tracking events (Mixpanel)

[rais38]

With current implementation, in screen tracking events at Mixpanel, our events are called "Screen view" always and there is not possibility to set from the DSL.

For this reason, I added ARMixpanelTrackedScreenEventName property in MixpanelProvider:

[ARAnalytics setupWithAnalytics: @{ /* keys */ } configuration: @{
   ARAnalyticsTrackedScreens: @[ @{
      ARAnalyticsClass: UIViewController.class,
      ARAnalyticsDetails: @[ @{
          ARAnalyticsPageNameKeyPath: @"title",
          ARAnalyticsProperties: ^NSDictionary*(UIViewController *controller, NSArray *parameters) {
                                                 return @{
                                                          ARMixpanelTrackedScreenEventName: @"custom_name"
                                                          };
                                             }
      }]
  }],
...

[orta]

Hey @rais38 - I think this is edge-case-y enough that it's worth making a subclass of this provider in your app code and using that in ARAnalytics instead. It adds cognitive load for someone understanding a specific provider vs how it is for the entire project, in theory could be generic to all providers but then t'd feel weird.

So, thanks for the PR! But I don't think this needs to come upstream!