LibWeb/CSS: Add support for translateZ() transform property

Author: https://github.com/kalenikaliaksandr
Commit: https://github.com/SerenityOS/serenity/commit/961b067df8
Pull-request: https://github.com/SerenityOS/serenity/pull/22105
Reviewed-by: https://github.com/AtkinsSJ ✅

Userland/Libraries/LibWeb/CSS/TransformFunctions.json

@@ -139,6 +139,14 @@
       }
     ]
   },
+  "translateZ": {
+    "parameters": [
+      {
+        "type": "<length>",
+        "required": true
+      }
+    ]
+  },
   "scale": {
     "parameters": [
       {

Userland/Libraries/LibWeb/CSS/Transformation.cpp

@@ -84,6 +84,13 @@ Gfx::FloatMatrix4x4 Transformation::to_matrix(Painting::PaintableBox const& pain
                 0, 0, 1, 0,
                 0, 0, 0, 1);
         break;
+    case CSS::TransformFunction::TranslateZ:
+        if (count == 1)
+            return Gfx::FloatMatrix4x4(1, 0, 0, 0,
+                0, 1, 0, 0,
+                0, 0, 1, value(0),
+                0, 0, 0, 1);
+        break;
     case CSS::TransformFunction::Scale:
         if (count == 1)
             return Gfx::FloatMatrix4x4(value(0), 0, 0, 0,