Consider a "dev mode" <WebView> tag API

[o0101]

Either inspired by:

• Chrome packaged apps WebView tag: https://developer.chrome.com/docs/extensions/reference/webviewTag/
• Electron's webview tag: https://www.electronjs.org/docs/latest/api/webview-tag

Both these primary sources are likely to change in future and BB supporting this feature with compatible (or likely comparable) APIs could serve these clients and be a stop gap measure for them to continue supporting their applications past the 2025 expiry horizon when these tech are sunset by the Chrome team