Warning GC27A339F: method 'collectionView:numberOfItemsInSection:' in protocol 'UICollectionViewDataSource'
Following warning is occurring in the iOS Project while building Xamarin.iOS (xamarin native application)

`TestApp.iOS/obj/iPhone/Debug/device-builds/iphone10.2-11.4/mtouch-cache/registrar.m(17,17): Warning GC27A339F: method 'collectionView:numberOfItemsInSection:' in protocol 'UICollectionViewDataSource' not implemented [-Wprotocol] (GC27A339F) (TestApp.iOS)`

When double click (navigate to details) on the waring navigates to following auto generated code.

```
@implementation MvvmCross_Platforms_Ios_Binding_Views_MvxBaseCollectionViewSource {
	XamarinObject __monoObjectGCHandle;
}

```
Expected behavior:
Warning should not come

Reproduction steps
Build the iOS application and check the Source -> Warnings

Configuration
Debug and Release

Version:
MVVMCross 6.4.2

Platform:
iphone: iOS - 11

Environment:
Visual studio for mac 8.7.8 (build 4)
Xamarin.iOS - Version: 14.0.0.0 (Visual Studio Community)
Mono 6.12.0.93 

Please let us know, whether this warning will be fixed in the upcoming release?
Whether this will cause any issue for iOS compliance? 