[Data sync] App freezes temporarily while new LOIs are being downloaded

[gino-m]

• App freezes after clicking "submit" - dragging the map causes app timeout
• Also freeze on any change to remove survey, jobs, or LOIs

[gino-m]

• Consider performing the marker and polygon initialization on a background thread to avoid blocking the main thread. Note that adding to the map will still need to be done on the main thread.
• Debouncing and only emitting unique LOI features in HomeScreenMapContainerViewModel avoids us from thrashing the UI when updated/new LOIs are trickling in:

   @OptIn(FlowPreview::class)
   mapLoiFeatures =
      activeSurvey.flatMapLatest {
        if (it == null) flowOf(setOf())
        else
          getLocationOfInterestFeatures(it)
            .debounce(1000.milliseconds)
            .distinctUntilChanged()
            .combine(this::updatedLoiSelectedStates)
      }

• FeatureManager.setFeatures() and downstream ClusterManager and *Render could be updated to add and remove featurs in batch rather than individually. <-- Maps SDK only allows these to be added one at a time.
• Note that ClusterManager.add() should also be renamed to put(), since the element with the existing tag name is replaced.

[gino-m]

Consider performing the marker and polygon initialization on a background thread to avoid blocking the main thread. Note that adding to the map will still need to be done on the main thread.

I tried only adding the markers and polygons on the UI thread, but there was no noticeable improvement.

[gino-m]

I just realized I was using the Profiler incorrectly, and learned something surprising. It's not the Maps SDK updates which are blocking - it appears to be the proto conversion process, which is happening on the main thread!