🔒 Fix XSS vulnerability in nv-modal

[manupawickramasinghe]

🎯 What: Fixed a Cross-Site Scripting (XSS) vulnerability in nv-modal.ts caused by injecting unescaped user input directly into the .innerHTML property of the modal body.
⚠️ Risk: If left unfixed, any external system, component, or user capable of triggering the nv-modal event could pass a malicious payload in the body field. This payload would then be executed within the context of the user's browser, potentially leading to session hijacking, unauthorized actions, or complete compromise of the application context.
🛡️ Solution: Imported the standard DOMPurify library and used DOMPurify.sanitize(this.mBody) to thoroughly clean and neutralize any potentially malicious input before assigning it to the DOM. Also added @types/dompurify for typescript type checking.

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PR created automatically by Jules for task 10182982558503608552 started by @manupawickramasinghe

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