Implement iPhone and Apple Watch preferences (#53)

apple/project.yml

@@ -31,6 +31,9 @@ targets:
       - Assets.xcassets
       - Sources/App
       - Generated/ironstorage_apple.swift
+    dependencies:
+      - target: IronStorageWatch
+        embed: true
     preBuildScripts:
       - name: Build Rust core
         basedOnDependencyAnalysis: false
@@ -78,6 +81,8 @@ targets:
       path: Watch-Info.plist
       properties:
         CFBundleDisplayName: IronStorage
+        WKApplication: true
         WKCompanionAppBundleIdentifier: de.rfc1437.ironstorage
     sources:
+      - Assets.xcassets
       - Sources/Watch