Added to the Pause Game Mode and Created a Pause Menu

-When the player presses the "Enter" key, the game will be paused, and the pause menu will show
-Added PauseMenu to GamePage.xaml
-Made it so the activeTime variable in Game1.cs will not be updated if the game is paused
Added a castle sprite for the player's castle

-Added Hitbox.cs and Projectile.cs
-Edited GetType in Action.cs to be GetActionType so it does not hide Object.GetType()
Merge branch 'PlayerCastle' into PauseGameMode
Merge branch 'PauseGameMode'