Refactor fluent download pipelines

Beam.Fluent/Core/FragmentMode.cs

@@ -0,0 +1,17 @@
+namespace Beam.Fluent;
+
+public enum FragmentMode {
+    Single,
+    Fragmented
+}
+
+public enum Channel {
+    Plain,
+    Stealth,
+    Playwright
+}
+
+public enum ContentKind {
+    Html,
+    Binary
+}