biggest gridinv update OF ALL TIME (#25834)

* add SaveItemLocation keybind

* make item direction public to avoid having to change between Angle for no reason

* add item location saving

* show

* Added a better save keybind, made it draw saved positions, and trying to save in a position it has already been saved in removes that position.

* w

* code style

* Make taken spots appear blue

* style

* !

---------

Co-authored-by: deltanedas <@deltanedas:kde.org>
Co-authored-by: notquitehadouken <tripwiregamer@gmail.com>
Co-authored-by: I.K <45953835+notquitehadouken@users.noreply.github.com>

Content.Shared/Storage/ItemStorageLocation.cs

@@ -8,16 +8,16 @@ public partial record struct ItemStorageLocation
     /// <summary>
     /// The rotation, stored a cardinal direction in order to reduce rounding errors.
     /// </summary>
-    [DataField]
-    private Direction _rotation;
+    [DataField("_rotation")]
+    public Direction Direction;
 
     /// <summary>
     /// The rotation of the piece in storage.
     /// </summary>
     public Angle Rotation
     {
-        get => _rotation.ToAngle();
-        set => _rotation = value.GetCardinalDir();
+        get => Direction.ToAngle();
+        set => Direction = value.GetCardinalDir();
     }
 
     /// <summary>