Qt WebEngine Changes in Qt 6

Things to change in Qt 6:

• Consider decoupling releases
  • Get rid of private dependencies
• Deduplicate code between quick and widgets
  • Unify Q[Quick]WebEngineProfile in core
  • Move QWebEnginePage to core
• Remove QQ Controls 1 backend (must)
• Get rid of startup and shutdown hacks
  • Chromium doesn't shut down itself clearly, so it's unclear what we can do here
• Consider switching all platforms or just all linux platforms to ozone
  • Chromium had plans to switch to Ozone for other platforms than linux, but didn't make progress...
• Rethink APIs that require deriving from QWebEnginePage
• Make default profile off-the-record
• Replace QWebEngineCallback with std::function
• Consider using a QtWebEngine namespace instead of prefixing every class with QWebEngineXXXX
• Move QWebEngineUrlRequestInterceptor to UI thread like everything else
  • Is done already?
• Consider removing non-essential API in QWebEngineView (that duplicates QWebEnginePage)
  • large portion of our users don't care about the page being separate though
  • It's useful for use cases like going full screen, where the full screen view is a separate thing
  • Also useful for loading things without a UI (off-screen)
• Consider deprecating ::printToPdf (if QPrinter supports PDF as backend)
• Making sure qml / c++ names are the same
• Rename "QWebEngine' (qml module) to QQuickWebEngine or QWebEngineQml
• add to core linker to remove all unnecessary exported symbols

  -Wl,--exclude-libs,ALL