Clean up SVG files and update logos

- Removed unnecessary XML and DOCTYPE declarations from SVG files.
- Eliminated comments within SVG files for cleaner output.
- Trimmed leading and trailing whitespace from SVG content.
- Ensured all SVG files end with a newline character.
- Updated multiple logo SVG files including WireGuard, Wise, WOG, Yahoo, and others to conform to the new standards.
- Enhanced the update-data.js script to automate the cleanup process for SVG files.

public/images/flags/cn.svg

@@ -8,4 +8,4 @@
   <use xlink:href="#cn-a" width="30" height="20" transform="matrix(-3.38573 -23.75998 23.75968 -3.38578 288 95.8)"/>
   <use xlink:href="#cn-a" width="30" height="20" transform="matrix(6.5991 -23.0749 23.0746 6.59919 288 168)"/>
   <use xlink:href="#cn-a" width="30" height="20" transform="matrix(14.9991 -18.73557 18.73533 14.99929 240 216)"/>
-</svg>
+</svg>