Add self verification after login

resources/qml/SelfVerificationCheck.qml

src/ChatPage.cpp

src/encryption/DeviceVerificationFlow.cpp

src/encryption/DeviceVerificationFlow.h

src/encryption/Olm.cpp

src/encryption/SelfVerificationStatus.cpp

src/encryption/SelfVerificationStatus.h

src/encryption/VerificationManager.cpp

src/encryption/VerificationManager.h