Add a Console device and start refactoring screen output.

Kernel/Console.h

@@ -0,0 +1,25 @@
+#pragma once
+
+#include <VirtualFileSystem/CharacterDevice.h>
+
+class Console final : public CharacterDevice {
+public:
+    static Console& the();
+
+    Console();
+    virtual ~Console() override;
+
+    virtual ssize_t read(byte* buffer, size_t size) override;
+    virtual ssize_t write(const byte* data, size_t size) override;
+
+private:
+    byte m_rows { 25 };
+    byte m_columns { 80 };
+    byte m_cursorRow { 0 };
+    byte m_cursorColumn { 0 };
+
+    byte m_currentAttribute { 0x07 };
+
+    const byte* s_vgaMemory { (const byte*)0xb8000 };
+};
+