Add profile support

Closes #231

src/Spectre.Console/Internal/Backends/Ansi/AnsiConsoleBackend.cs

@@ -0,0 +1,66 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using Spectre.Console.Rendering;
+
+namespace Spectre.Console
+{
+    internal sealed class AnsiConsoleBackend : IAnsiConsoleBackend
+    {
+        private readonly AnsiBuilder _builder;
+        private readonly Profile _profile;
+
+        public IAnsiConsoleCursor Cursor { get; }
+
+        public AnsiConsoleBackend(Profile profile)
+        {
+            _profile = profile ?? throw new ArgumentNullException(nameof(profile));
+            _builder = new AnsiBuilder(profile);
+
+            Cursor = new AnsiConsoleCursor(this);
+        }
+
+        public void Clear(bool home)
+        {
+            Render(new[] { Segment.Control("\u001b[2J") });
+
+            if (home)
+            {
+                Cursor.SetPosition(0, 0);
+            }
+        }
+
+        public void Render(IEnumerable<Segment> segments)
+        {
+            var builder = new StringBuilder();
+            foreach (var segment in segments)
+            {
+                if (segment.IsControlCode)
+                {
+                    builder.Append(segment.Text);
+                    continue;
+                }
+
+                var parts = segment.Text.NormalizeNewLines().Split(new[] { '\n' });
+                foreach (var (_, _, last, part) in parts.Enumerate())
+                {
+                    if (!string.IsNullOrEmpty(part))
+                    {
+                        builder.Append(_builder.GetAnsi(part, segment.Style));
+                    }
+
+                    if (!last)
+                    {
+                        builder.Append(Environment.NewLine);
+                    }
+                }
+            }
+
+            if (builder.Length > 0)
+            {
+                _profile.Out.Write(builder.ToString());
+                _profile.Out.Flush();
+            }
+        }
+    }
+}