Grid Sync: reordering from the web is not reflected on the app

### Expected behavior

When reordering podcasts on the web version, this change should be reflected on the app.

### Actual behavior

When reordering podcasts on the web version, the order is not reflected on the app.

### Steps to reproduce the behavior

1. Have both the iOS app and the web player opened
2. On the web player, reorder your podcast list
3. Refresh the app
4. Check that the order is not reflected5.

https://user-images.githubusercontent.com/7040243/183443319-c7abf033-4b0f-47c0-852e-2df43af26a80.mov

### Additional information

* The steps mentioned above work fine on Android — the new order is reflected
* If I change the order on the Android app, the iPhone version reflects it normally

I think we might be running into (possible) two different issues here:

* The new order is returned correctly for Android but not for iOS (due to the usage of Protobuf?)
* The web player is hitting a different endpoint that for some reason doesn't get its changes reflected on the iOS app

@srjakes @geekygecko can I get your help with this since it seems related to the API?

##### Tested on iPhone 13 Pro and simulator, iOS 15, Pocket Casts 7.20.2

Start by reproducing the iOS sync behavior with the web player, then trace the iOS API synchronization path and compare its returned order with Android, including the possible Protobuf handling mentioned in the issue. Done means podcast reordering from the web is reflected after refreshing the iOS app and the behavior remains covered by an appropriate test.

Written by the indexing model from the issue text.