Refactor code structure for improved readability and maintainability

Remove debugging border from the websr plugin's styling

Enhance canvas sizing logic in artplayer-plugin-websr

- Updated canvas positioning to center it within the player.
- Introduced a new function to calculate canvas size based on the video aspect ratio.
- Adjusted canvas dimensions during initialization and on resize events to maintain aspect ratio.
- Ensured canvas styles are updated to reflect the calculated dimensions.

feat: add comparison mode to artplayer-plugin-websr

- Updated README.md to reflect new comparison feature and simplified content.
- Modified package.json to remove unnecessary keywords.
- Enhanced index.js to implement comparison functionality, allowing users to compare original and upscaled video.
- Added new methods for enabling, disabling, and toggling comparison mode, as well as setting and getting the comparison position.
- Updated TypeScript definitions to include new comparison options and methods.

docs/assets/example/websr.js

@@ -0,0 +1,16 @@
+// npm i artplayer-plugin-websr
+// import artplayerPluginWebsr from 'artplayer-plugin-websr';
+
+var art = new Artplayer({
+    container: ".artplayer-app",
+    url: "/assets/sample/video3.mp4",
+    fullscreenWeb: true,
+    plugins: [
+        artplayerPluginWebsr({
+            scale: 2,
+            compare: true,
+            weights: "/assets/websr/cnn-2x-m-an.json",
+            networkName: "anime4k/cnn-2x-m",
+        }),
+    ],
+});