Webview Desktop - CookieManager is not used by the actual webview

[threethan]

The cookie manager accessible through WebViewState.cookieManager() is not the same one used by the web view itself.

• It is possible to read and write persistent cookies using WebViewState.cookieManager(), but they won't be used by the WebView
• The WebView can read and write cookies, but they won't be accessible through WebViewState.cookieManager() and will not persist

This means that cookies cannot be read or written as expected on desktop ( #152 )

Explanation:

• WebViewState.cookieManager() is backed by CefCookieManager.getGlobalManager() which stores cookies only for CefRequestContext.getGlobalContext() [DesktopCookieManager.kt]
• WebView.defaultWebViewFactory(param) uses a custom CefRequestContext ("createModifiedRequestContext") which differs from the global one [WebView.desktop.kt] [CefRequestExt.kt]