* Changes covered by this PR:
- Removed unused references
- Removed Xamarin.PreBuilt.iOS.app.zip since it's now built and included automatically as part of the CI build
- Added missing signing and versioning
- Replaced DotNetZip with System.IO.Compression.ZipFile: now that .net provides its own zip implementation we no longer require DotNetZip reference for unzipping purposes
- Fixes the Tasks missing CodePages reference: we no longer need to replace the CodePages reference assembly by its implementation, since this project already specifies the `win` RID. The replacement was failing because `RuntimeTargetsCopyLocalItems` is empty now that the RID is set, so we ended up removing the reference.
Co-authored-by: Emanuel Fernandez Dell'Oca <ema@xamarin.com>