Refactored the UI module and the handlers module to do a more chain-of-responsibility method to manage the UI's and handlers for different key events. Also, initial work for indexer settings as well

src/ui/radarr_ui/downloads/downloads_ui_tests.rs

@@ -0,0 +1,19 @@
+#[cfg(test)]
+mod tests {
+  use strum::IntoEnumIterator;
+
+  use crate::app::radarr::{ActiveRadarrBlock, DOWNLOADS_BLOCKS};
+  use crate::ui::radarr_ui::downloads::DownloadsUi;
+  use crate::ui::DrawUi;
+
+  #[test]
+  fn test_downloads_ui_accepts() {
+    ActiveRadarrBlock::iter().for_each(|active_radarr_block| {
+      if DOWNLOADS_BLOCKS.contains(&active_radarr_block) {
+        assert!(DownloadsUi::accepts(active_radarr_block.into()));
+      } else {
+        assert!(!DownloadsUi::accepts(active_radarr_block.into()));
+      }
+    });
+  }
+}