Add abseil dependency and enhance vcpkg configuration

- Introduced the abseil library as a dependency in vcpkg.json, excluding UWP platform support.
- Updated the vcpkg configuration to include a new features section for pkg-config, improving dependency detection.
- Modified yaze.vcxproj to conditionally include additional dependencies and library directories based on vcpkg integration status, enhancing build flexibility.
- Organized source and header files in the project structure for better clarity and maintainability.

vcpkg.json

@@ -15,6 +15,10 @@
       "name": "sdl2",
       "platform": "!uwp",
       "features": ["vulkan"]
+    },
+    {
+      "name": "abseil",
+      "platform": "!uwp"
     }
   ],
   "builtin-baseline": "c8696863d371ab7f46e213d8f5ca923c4aef2a00",
@@ -23,5 +27,11 @@
       "name": "abseil",
       "version": "20240116.2"
     }
-  ]
+  ],
+  "features": {
+    "pkg-config": {
+      "description": "Use pkg-config for dependency detection",
+      "dependencies": []
+    }
+  }
 }