Add global usings (#668)

* Use global usings

* Fix namespace declarations for test projects

src/Spectre.Console/Rendering/Borders/Boxes/AsciiBoxBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Boxes/DoubleBoxBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Boxes/HeavyBoxBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Boxes/RoundedBoxBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Boxes/SquareBoxBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Tables/Ascii2TableBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Tables/AsciiDoubleHeadTableBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Tables/AsciiTableBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Tables/DoubleEdgeTableBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Tables/DoubleTableBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Tables/HeavyEdgeTableBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Tables/HeavyHeadTableBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Tables/HeavyTableBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Tables/HorizontalTableBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Tables/MarkdownTableBorder.cs

@@ -1,7 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Tables/MinimalDoubleHeadTableBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Tables/MinimalHeavyHeadTableBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Tables/MinimalTableBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Tables/RoundedTableBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Tables/SimpleHeavyTableBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Tables/SimpleTableBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Borders/Tables/SquareTableBorder.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/IAnsiConsoleEncoder.cs

@@ -1,5 +1,3 @@
-using System.Collections.Generic;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/IRenderHook.cs

@@ -1,5 +1,3 @@
-using System.Collections.Generic;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/JustInTimeRenderable.cs

@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Measurement.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/RenderContext.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/RenderHookScope.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/RenderPipeline.cs

@@ -1,5 +1,3 @@
-using System.Collections.Generic;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Renderable.cs

@@ -1,6 +1,3 @@
-using System.Collections.Generic;
-using System.Diagnostics;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Segment.cs

@@ -1,10 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Diagnostics;
-using System.Linq;
-using System.Text;
-using Wcwidth;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/SegmentLine.cs

@@ -1,6 +1,3 @@
-using System.Collections.Generic;
-using System.Linq;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/SegmentLineEnumerator.cs

@@ -1,6 +1,3 @@
-using System.Collections;
-using System.Collections.Generic;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/SegmentLineIterator.cs

@@ -1,6 +1,3 @@
-using System.Collections;
-using System.Collections.Generic;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/SegmentShape.cs

@@ -1,7 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-
 namespace Spectre.Console.Rendering;
 
 internal readonly struct SegmentShape

src/Spectre.Console/Rendering/Tree/AsciiTreeGuide.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Tree/BoldLineTreeGuide.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Tree/DoubleLineTreeGuide.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>

src/Spectre.Console/Rendering/Tree/LineTreeGuide.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Spectre.Console.Rendering;
 
 /// <summary>