Some tests were disabled by a crashpad patch because the changes to make
them work with new SDK are relatively big and no need to backport them.
Fixes#4353.
Also implement panels that appear in all spaces on macOS.
Using them for calls panels and custom notifications, so it
will be possible to use custom notifications in macOS as well.
This will allow us to use C++14 library on all platforms.
Patches for macold versions got bigger and are now different for
crashpad and mini_chromium, so they were moved to a separate folder.
John Preston
Vasilii Babich