add hotkey/modifier help in frames

[namdre]

after https://github.com/eclipse/sumo/issues/10900

Additional / Stops / Wire: Control for moving without creating elements Move mode / vehicle / Additional / Stops / Persons / Container / Wire / Data: Alt + Click for marking front elements

[palvarezlopez]

@namdre We have already a Information box. What is the missing information?

[namdre]

You are showing the 'create edge frame'. This ticket is about 'move mode'

[namdre]

And this is only needed after #10900

[palvarezlopez]

I read it too quickly 😅😅