Deploy external data in QtWebEngineCore.framework for framework builds

There is currently no convenient way to deploy QtWebEngine into an application
bundle on OSX. macdeployqt copies frameworks into a .app bundle's Frameworks
directory but this makes no sense unless all the needed files are also
distributed with the bundle.

This patch moves:
- The ffmpegsumo.so library into Libraries/
- Locale .pak files, qtwebengine_resources.pak and icudtl.dat into Resources/
- QtWebEngineProcess into its own .app bundle, itself into Helpers/

QMAKE_BUNDLE_DATA is used to copy files into the bundle while INSTALLS is
used when installing normally. A LOCALE_LIST is explicitly listed since
QMAKE_BUNDLE_DATA can't handle the * glob to match all source files.

Change-Id: I5c0df57b4b9e93f9cce34a74a6e024bf90d37b5c
Task-number: QTBUG-41611
Reviewed-by: Zeno Albisser <zeno.albisser@digia.com>
Reviewed-by: Andras Becsi <andras.becsi@digia.com>