Implemented invincibility

-Right-click right now to use it and see its effects, both visually and how enemies can no longer hurt the player's castle
Created an Armored Enemy and Archer helper for the Player

-The armored enemy can only be harmed with the Warhammer
-Created an Archer helper for the player, who runs on a timer and will decide whether to attack an enemy or not
  -Enemies that are considered must be within the Archer's range and must not be resistant to the Sword
Created Saving and Loading Data

-Created Data.cs
-Created the PlayerData class
-Coded methods for saving and loading the player data
-Added a Save button to GamePage.xaml
Added support for saving and loading PlayerHelpers

-Added HelperData.cs and ArcherData.cs
-Added flexible methods for easily converting PlayerHelpers to HelperDatas and vice versa
Added Transparency to the Weapon Buttons on GamePage.xaml

-Made the buttons 70% transparent when in the Normal visual state
-When a pointer is hovered on the buttons or the button are tapped/clicked, the buttons become 100% transparent
Created the Spear weapon's graphic
Merge branch 'SpearGraphic'