feat(frontend): enhance link rendering and markdown processing

- Added LinkUtils for detecting and rendering NomadNet and standard links in text.
- Introduced MarkdownRenderer for converting Markdown to HTML, including support for code blocks, headers, and inline formatting.
- Implemented escapeHtml utility function to prevent XSS in rendered text.
- Updated ToastUtils to support an optional key parameter for toast notifications.
- Included Italian language support in the frontend localization.

electron/main.js

@@ -348,9 +348,9 @@ app.whenReady().then(async () => {
             "default-src 'self'",
             "script-src 'self' 'unsafe-inline' 'unsafe-eval'",
             "style-src 'self' 'unsafe-inline'",
-            "img-src 'self' data: blob: https://*.tile.openstreetmap.org https://tile.openstreetmap.org",
+            "img-src 'self' data: blob: https://*.tile.openstreetmap.org https://tile.openstreetmap.org https://*.cartocdn.com",
             "font-src 'self' data:",
-            "connect-src 'self' http://localhost:9337 https://localhost:9337 ws://localhost:* wss://localhost:* blob: https://*.tile.openstreetmap.org https://tile.openstreetmap.org https://nominatim.openstreetmap.org https://git.quad4.io",
+            "connect-src 'self' http://localhost:9337 https://localhost:9337 ws://localhost:* wss://localhost:* blob: https://*.tile.openstreetmap.org https://tile.openstreetmap.org https://nominatim.openstreetmap.org https://git.quad4.io https://*.cartocdn.com",
             "media-src 'self' blob:",
             "worker-src 'self' blob:",
             "frame-src 'self'",