Update window open handler to accept new allowlisted protocols

[sergeichestakov]

Why

Follow on to #151, I missed a spot here when I updated our allowlisted protocols to include replit:// and vscode://. We need to update the window open handler logic to match that of the will-navigate event handler to account for URLs opened via target="_blank" and programmatically via window.open. This ensures the behavior will be consistent to what we see in the will-navigate handler which fires in all other cases.

What changed

Update window open handler to accept new allowlisted protocols to match what we do in the will nav handler so that target=_blank and window.open work as expected.

Test plan

• Open desktop app in dev
• Open browser console
• Enter window.open("replit://new")
• Previously (on main) this be a no-op and not do anything
• Now, this will open a new Replit window to the new repl flow as expected

[szymonkaliski]

nice!