AdditionalAppExtensions: ITMS-90075: "This bundle is invalid. The application-identifier entitlement is missing

### Steps to Reproduce

`dotnet publish` app using `AdditionalAppExtensions` & custom Entitlements (e.g. App Groups) & upload it to App Store Connect (using the Transporter app)

### Expected Behavior

Build is accepted

### Actual Behavior

`ERROR ITMS-90075: "This bundle is invalid. The application-identifier entitlement is missing; it should contain your 10-character Apple Developer ID, followed by a dot, followed by your bundle identifier."
`

It appears that most developers trying to use AdditionalAppExtensions will be facing this problem, as can be seen [here](https://github.com/xamarin/xamarin-macios/issues/8933#issuecomment-759733011) or [here](https://github.com/xamarin/xamarin-macios/issues/8933#issuecomment-705901996).

### Environment
.NET8 RC2

### Workaround

I created a shell script that adds the property before building the app (and removes it again after because `Debug`-builds fail if it is present)

```
/usr/libexec/PlistBuddy -c 'add application-identifier string XXXXXXXXXX.my.app.ShareExtension' ../native/ShareExtension.entitlements
xcodebuild -project ../native/diarium.xcodeproj -configuration Release -target ShareExtension -sdk "iphoneos"
dotnet publish
/usr/libexec/PlistBuddy -c 'remove application-identifier' ../native/ShareExtension.entitlements
```