callbuttons: create alternate layouts

qml.qrc

resources/icons/ontheside_black_24dp.svg

resources/icons/onthetop_black_24dp.svg

src/app/appsettingsmanager.h

src/app/calladapter.cpp

src/app/constant/JamiStrings.qml

src/app/mainview/components/CallActionBar.qml

src/app/mainview/components/CallOverlay.qml

src/app/mainview/components/OngoingCallPage.qml

src/app/mainview/components/ParticipantsLayer.qml

src/app/mainview/components/ParticipantsLayoutHorizontal.qml

src/app/mainview/components/ParticipantsLayoutVertical.qml