[Spec] Remove Application.Properties

[hartez]

Description

Remove the Application.Properties key/value store from Forms in favor of the Essentials Preferences key/value store.

Forms currently provides a rudimentary key/value store using Application.Properties.

Essentials provides a similar but more robust option with Preferences. Additionally, Essentials includes a Secure Storage option.

We should remove the Forms Application.Properties feature in favor of the Essentials version. See also #19.

API

Remove:

System.Collections.Generic.IDictionary<string,object> Xamarin.Forms.Application.Properties { get; }

Xamarin.Forms.Internals.IDeserializer

Xamarin.Forms.Platform.UWP.WindowsSerializer

Xamarin.Forms.Platform.iOS.Deserializer

Xamarin.Forms.Platform.Android.Deserializer

Backward Compatibility

Users of the Properties feature will need to modify their code to use the Preferences feature.

Difficulty : Low

Mostly just deleting code - the Properties code, and also the various IDeserializer implementations.

[jamesmontemagno]

I give this a big 👍

Additionally, devs can always write files to disk and serialize and deserialize for complex data structures.