login-sessions: Rename the "Plasma" session to "Plasma (X11)"

This clarifies that there are two session types, and makes it easy
to distinguish what type of session is being used.

login-sessions/CMakeLists.txt

 ## For Plasma end users
 
-configure_file(plasma.desktop.cmake ${CMAKE_CURRENT_BINARY_DIR}/plasma.desktop)
+configure_file(plasmax11.desktop.cmake ${CMAKE_CURRENT_BINARY_DIR}/plasmax11.desktop)
 install(FILES
-        ${CMAKE_CURRENT_BINARY_DIR}/plasma.desktop
+        ${CMAKE_CURRENT_BINARY_DIR}/plasmax11.desktop
         DESTINATION ${KDE_INSTALL_DATADIR}/xsessions
 )
 

login-sessions/plasma.desktop.cmake → login-sessions/plasmax11.desktop.cmake

@@ -3,7 +3,7 @@ Type=XSession
 Exec=${CMAKE_INSTALL_FULL_BINDIR}/startplasma-x11
 TryExec=${CMAKE_INSTALL_FULL_BINDIR}/startplasma-x11
 DesktopNames=KDE
-Name=Plasma
+Name=Plasma (X11)
 Name[ar]=بلازما
 Name[ast]=Plasma
 Name[az]=Plasma