Improve DevicesPage and DevicesModel

- Split the list into sections for "this devices", "verified devices", "unverified devices", and "devices without encryption support"
- Sort the lists by last activity

src/CMakeLists.txt

@@ -64,6 +64,7 @@ add_library(neochat STATIC
     chatdocumenthandler.h
     models/devicesmodel.cpp
     models/devicesmodel.h
+    models/devicesproxymodel.cpp
     filetypesingleton.cpp
     filetypesingleton.h
     login.cpp