LibWeb: Add missing MEDIAQUERIES-5 media-features

This adds (or at least stubs-out) the following:
- display-mode
- dynamic-range
- environment-blending
- forced-colors
- horizontal-viewport-segments
- vertical-viewport-segments
- inverted-colors
- nav-controls
- prefers-contrast
- prefers-reduced-data
- prefers-reduced-motion
- prefers-reduced-transparency
- scripting
- video-color-gamut
- video-dynamic-range

The `@media (inverted-colors)` CSS that the spec requires we add to the
UA style sheet does not actually do anything for us yet since we don't
support `filter`, but it seemed sensible to include it now to avoid
forgetting later. :^)

Userland/Libraries/LibWeb/CSS/Default.css

@@ -306,3 +306,13 @@ mark {
  * https://html.spec.whatwg.org/multipage/rendering.html#embedded-content-rendering-rules
  */
 iframe { border: 2px inset; }
+
+/* https://www.w3.org/TR/mediaqueries-5/#descdef-media-inverted-colors
+ */
+@media (inverted-colors) {
+    img:not(picture>img),
+    picture,
+    video {
+        filter: invert(100%);
+    }
+}

Userland/Libraries/LibWeb/CSS/MediaFeatures.json

@@ -58,6 +58,37 @@
             "<length>"
         ]
     },
+    "display-mode": {
+        "type": "discrete",
+        "values": [
+            "fullscreen",
+            "standalone",
+            "minimal-ui",
+            "browser"
+        ]
+    },
+    "dynamic-range": {
+        "type": "discrete",
+        "values": [
+            "standard",
+            "high"
+        ]
+    },
+    "environment-blending": {
+        "type": "discrete",
+        "values": [
+            "opaque",
+            "additive",
+            "subtractive"
+        ]
+    },
+    "forced-colors": {
+        "type": "discrete",
+        "values": [
+            "none",
+            "active"
+        ]
+    },
     "grid": {
         "type": "discrete",
         "values": [
@@ -70,6 +101,12 @@
             "<length>"
         ]
     },
+    "horizontal-viewport-segments": {
+        "type": "range",
+        "values": [
+            "<integer>"
+        ]
+    },
     "hover": {
         "type": "discrete",
         "values": [
@@ -77,12 +114,26 @@
             "hover"
         ]
     },
+    "inverted-colors": {
+        "type": "discrete",
+        "values": [
+            "none",
+            "inverted"
+        ]
+    },
     "monochrome": {
         "type": "range",
         "values": [
             "<integer>"
         ]
     },
+    "nav-controls": {
+        "type": "discrete",
+        "values": [
+            "none",
+            "back"
+        ]
+    },
     "orientation": {
         "type": "discrete",
         "values": [
@@ -120,6 +171,36 @@
             "dark"
         ]
     },
+    "prefers-contrast": {
+        "type": "discrete",
+        "values": [
+            "no-preference",
+            "less",
+            "more",
+            "custom"
+        ]
+    },
+    "prefers-reduced-data": {
+        "type": "discrete",
+        "values": [
+            "no-preference",
+            "reduce"
+        ]
+    },
+    "prefers-reduced-motion": {
+        "type": "discrete",
+        "values": [
+            "no-preference",
+            "reduce"
+        ]
+    },
+    "prefers-reduced-transparency": {
+        "type": "discrete",
+        "values": [
+            "no-preference",
+            "reduce"
+        ]
+    },
     "resolution": {
         "type": "range",
         "values": [
@@ -134,6 +215,14 @@
             "progressive"
         ]
     },
+    "scripting": {
+        "type": "discrete",
+        "values": [
+            "none",
+            "initial-only",
+            "enabled"
+        ]
+    },
     "update": {
         "type": "discrete",
         "values": [
@@ -142,6 +231,27 @@
             "fast"
         ]
     },
+    "vertical-viewport-segments": {
+        "type": "range",
+        "values": [
+            "<integer>"
+        ]
+    },
+    "video-color-gamut": {
+        "type": "discrete",
+        "values": [
+            "srgb",
+            "p3",
+            "rec2020"
+        ]
+    },
+    "video-dynamic-range": {
+        "type": "discrete",
+        "values": [
+            "standard",
+            "high"
+        ]
+    },
     "width": {
         "type": "range",
         "values": [