Frontend Speedup (#2183) * Update jQuery to the latest version * Optimize images by adding lazy loading * Remove unnecessary jQuery calls * Speed up the loading of the mainmenu * Optimize loading screen: use DOMContentLoaded and defer jQuery * Replace jQuery to JavaScript * Fix the screen resolution glitch when game start up * Fix the code style to the current code base * Returning the js script binding to the head block * Remove unnecessary changes --------- Co-authored-by: Rubat <3299036+robotboy655@users.noreply.github.com>