Massive Namespace Cleanup (#1544)

* Removed the Interfaces folder.
* All objects inside the GameObjects subfolders are now in the GameObjects namespace.
* Added a Resharper DotSettings file to mark the GameObjects subfolders as not providing namespaces.
* Simplified Robust.client.Graphics namespace.
* Automated remove redundant using statements.

Robust.Client/Graphics/IFontManager.cs

@@ -0,0 +1,78 @@
+using System.IO;
+using System.Text;
+
+namespace Robust.Client.Graphics
+{
+    public interface IFontManager
+    {
+
+    }
+
+    internal interface IFontManagerInternal : IFontManager
+    {
+        IFontFaceHandle Load(Stream stream);
+        IFontInstanceHandle MakeInstance(IFontFaceHandle handle, int size);
+        void Initialize();
+    }
+
+    internal interface IFontFaceHandle
+    {
+
+    }
+
+    internal interface IFontInstanceHandle
+    {
+
+
+        Texture? GetCharTexture(Rune codePoint, float scale);
+        Texture? GetCharTexture(char chr, float scale) => GetCharTexture((Rune) chr, scale);
+        CharMetrics? GetCharMetrics(Rune codePoint, float scale);
+        CharMetrics? GetCharMetrics(char chr, float scale) => GetCharMetrics((Rune) chr, scale);
+
+        int GetAscent(float scale);
+        int GetDescent(float scale);
+        int GetHeight(float scale);
+        int GetLineHeight(float scale);
+    }
+
+    /// <summary>
+    ///     Metrics for a single glyph in a font.
+    ///     Refer to https://www.freetype.org/freetype2/docs/glyphs/glyphs-3.html for more information.
+    /// </summary>
+    public readonly struct CharMetrics
+    {
+        /// <summary>
+        ///     The horizontal distance between the origin and the left of the drawn glyph.
+        /// </summary>
+        public readonly int BearingX;
+
+        /// <summary>
+        ///     The vertical distance between the origin and the top of the drawn glyph.
+        /// </summary>
+        public readonly int BearingY;
+
+        /// <summary>
+        ///     How much to advance the origin after drawing the glyph.
+        /// </summary>
+        public readonly int Advance;
+
+        /// <summary>
+        ///     The width of the drawn glyph.
+        /// </summary>
+        public readonly int Width;
+
+        /// <summary>
+        ///     The height of the drawn glyph.
+        /// </summary>
+        public readonly int Height;
+
+        public CharMetrics(int bearingX, int bearingY, int advance, int width, int height)
+        {
+            BearingX = bearingX;
+            BearingY = bearingY;
+            Advance = advance;
+            Width = width;
+            Height = height;
+        }
+    }
+}