GHSA-5p82-2q3r-wj3m: ThingsBoard allows an authenticated user to upload malicious SVG images

ThingsBoard in versions prior to v4.2.1 allows an authenticated user to upload malicious SVG images via the "Image Gallery", leading to a Stored Cross-Site Scripting (XSS) vulnerability. The exploit can be triggered when any user accesses the public API endpoint of the malicious SVG images, or if the malicious images are embedded in an `iframe` element, during a widget creation, deployed to any page of the platform (e.g., dashboards), and accessed during normal operations. The vulnerability resides in the `ImageController`, which fails to restrict the execution of JavaScript code when an imag…