Removes unneeded methods/properties in abstraction, removes unneeded usages of it, changes everything to pre-defined bundles, fixes cdf implementation and reduces reflection, renames namespace

src/Umbraco.Core/WebAssets/JavascriptFile.cs

@@ -0,0 +1,14 @@
+namespace Umbraco.Core.WebAssets
+{
+    /// <summary>
+    /// Represents a JS asset file
+    /// </summary>
+    public class JavaScriptFile : AssetFile
+    {
+        public JavaScriptFile(string filePath)
+            : base(AssetType.Javascript)
+        {
+            FilePath = filePath;
+        }
+    }
+}