Avoid duplicate routing.json calls when presenting routing results card (#398)

Author: nighthawk

Sources/TripKitUI/view model/TKUIRoutingResultsViewModel+CalculateRoutes.swift

@@ -113,6 +113,7 @@ extension TKUIRoutingResultsViewModel {
 
     // When changing modes, force refresh
     let refresh: Observable<BuilderInput> = inputs.changedModes.asObservable()
+      .debounce(.seconds(1), scheduler: MainScheduler.instance)
       .map { _ in (date: nil, search: nil, pin: nil, forceRefresh: true) }
 
     // When changing date, switch to that date

Sources/TripKitUI/view model/TKUIRoutingResultsViewModel.swift

@@ -81,9 +81,9 @@ class TKUIRoutingResultsViewModel {
       requestChanged = Observable.merge(
         originOrDestinationChanged,
         builderChangedWithID
-          .debounce(.seconds(1), scheduler: MainScheduler.instance)
       )
         .distinctUntilChanged { $0.1 == $1.1 } // only generate a new request object if necessary
+        .debounce(.milliseconds(100), scheduler: MainScheduler.instance)
         .map { ($0.0.generateRequest(), $0.1) }
         .startWith( (initialRequest, initialRequest.map { Self.buildId(for: $0.builder) } ) )
         .distinctUntilChanged { $0.1 == $1.1 } // ignore duplicated request objects (happens when initialRequest != nil)