LibWeb: Implement linear easing according to latest spec

Author: https://github.com/Gingeh
Commit: c67ecf37f7
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2151
Reviewed-by: https://github.com/AtkinsSJ ✅

Tests/LibWeb/Text/input/WebAnimations/misc/easing-parsing.html

@@ -13,6 +13,7 @@
             "linear(5% 0, 10% 0.5, 100% 1)",
             "linear(5% 0, 1 100%)",
             "linear(-14, 27 210%)",
+            "linear(0.5 5% 10%)",
             "ease",
             "ease-in",
             "ease-out",
@@ -39,7 +40,6 @@
             "linear(5 10)",
             "linear(5% 10%)",
             "linear(0.5 5% 10)",
-            "linear(0.5 5% 10%)",
             "cubic-bezier(0, 0, 0)",
             "cubic-bezier(2, 0, 0, 0)",
             "cubic-bezier(0, 0, 2, 0)",