feat: add allowFileDownloads and suppressJavaScriptDialogs props

[Nodonisko]

Add two new props:

allowFileDownloads - block all downloads that could be triggered by WebView (could be toggled during runtime)
suppressJavaScriptDialogs - block all JS dialogs (alert/prompt/confirm) (could be toggled during runtime)

I also added code to test these props to example app and fixed some TS errors by creating proper tsconfig.json for example app.

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Note

Adds new runtime-configurable props and wires them through native code and types.

• New props: suppressJavaScriptDialogs (Android, iOS) to block alert/confirm/prompt; allowFileDownloads (Android) to disable all downloads
• Android: gate downloads in RNCWebView, RNCWebViewManagerImpl DownloadListener, and BlobFileDownloader; add JS dialog suppression via RNCWebChromeClient (onJsAlert/Confirm/Prompt) with shouldSuppressDialogs(); expose props via old/new arch managers
• iOS: suppress JS dialogs in RNCWebViewImpl by short-circuiting alert/confirm/prompt handlers; export prop in RNCWebViewManager.mm and map in RNCWebView.mm
• Types/bridge: add props to RNCWebViewNativeComponent.ts and WebViewTypes.ts
• Docs/examples: document both props in docs/Reference.md; add toggles and demos in example/examples/Alerts.tsx and Downloads.tsx; add example tsconfig.json and update metro.config.js

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