Make palette global in Qml

CMakeLists.txt

resources/qml/Avatar.qml

resources/qml/Completer.qml

resources/qml/EncryptionIndicator.qml

resources/qml/ForwardCompleter.qml

resources/qml/ImageButton.qml

resources/qml/MatrixText.qml

resources/qml/MatrixTextField.qml

resources/qml/MessageInput.qml

resources/qml/MessageView.qml

resources/qml/NhekoBusyIndicator.qml

resources/qml/QuickSwitcher.qml

resources/qml/Reactions.qml

resources/qml/ReplyPopup.qml

resources/qml/RoomSettings.qml

resources/qml/TimelineRow.qml

resources/qml/TimelineView.qml

resources/qml/TopBar.qml

resources/qml/TypingIndicator.qml

resources/qml/UserProfile.qml