Long press to open new window sometimes unresponsive in UWP app

[Jaifroid]

In the UWP app in Service Worker mode, the ability to open a new tab with long press appears to be broken (opening a new window with right-click or middle-click still works). In the Electron app, the same long-press gesture works fine.

This regression affects only a tiny minority of users, as the feature is only available on a PC or tablet, where another pointing device such as a mouse is usually available (the feature is not supported on Windows Mobile). It may be worth re-working this as part of #278, given that the most sensible use of long press would be to open a preview, and that preview would then include an option to open the previewed page in a new window.

[Jaifroid]

On further investigation, the feature isn't broken, it's just very fiddly to get the long press to register.

[Jaifroid]

This is an issue related to the legacy webview. Can't fix.