Add user _id to createTrip

[lmeier]

We actually don't need any change for setting the trip to the one returned as we already have that: https://github.com/radarlabs/radar-sdk-ios/blob/liammeier/fence-1902-send-user-on-starttrip-and-update-tripoptions-with-trip/RadarSDK/Radar.m#L491-L492

[york-wei]

@lmeier it looks like trip options is just set to the one passed in the startTrip, I think we need to create a new one with the returned trip's externalId

+ (void)startTripWithOptions:(RadarTripOptions *)tripOptions
             trackingOptions:(RadarTrackingOptions *)trackingOptions
           completionHandler:(RadarTripCompletionHandler)completionHandler {
    [[RadarLogger sharedInstance] logWithLevel:RadarLogLevelInfo type:RadarLogTypeSDKCall message:@"startTrip()"];
    [[RadarAPIClient sharedInstance] createTripWithOptions:tripOptions
                                         completionHandler:^(RadarStatus status, RadarTrip *trip, NSArray<RadarEvent *> *events) {
                                             if (status == RadarStatusSuccess) {
                                                 [RadarSettings setTripOptions:tripOptions];

[york-wei]

Looks like we need to update the RadarTrip class to include scheduledArrivalAt and parse it from the JSON payload

[KennyHuRadar]

This seems like a breaking change, would we need migration docs?

A follow up question is, do we want to keep on exposing these "init by fields" functions when we already expose the "init by dictionary" functions as we revamp the SDK for one line implementation? The upside would be that we will no longer be collecting deprecated interfaces. The downside would be that initializing from dictionary in native is kinda annoying and not developer friendly. However, one may also claim that with one line implementation all of these options that developers are currently building and loading into the client should be loaded in from the server.

[lmeier]

Correct, we shouldn't break this here. I'll either introduce another option with the 2 additional params or create a dictionary based initialization.