Check if edge webview runtime is available in the call to
wxWebView::IsBackendAvailable() instead of only doing it during
process initialization. This allows an application to install
the Edge WebView2 Runtime during runtime and use the edge webview
afterwards without restarting the process.
Tell the SDK controller if the control is shown or hidden.
This allows creating a hidden webview which will be shown later
and might fix other potential issues.
The new method allows to set the zoom level more precisely than the
existing SetZoom(wxWebViewZoom).
Also improve the webview sample by using radio menu items instead of
check items and manually resetting them.
Closes https://github.com/wxWidgets/wxWidgets/pull/1894Closes#18769.
